YourPhone.ScreenMirroring.Managed Initializes a new instance of the class. This action launches the Android intent associated with the notification. It involves sending a message from PC to phone. Gets the number of frames in the animation. Gets the frame rate of the animation. Gets the duration of the animation. Converts a zero-based frame number to the corresponding progress value denoting the start of the frame. Returns a map from marker names to corresponding progress values. Sets the color property with the given name, or does nothing if no such property exists. Sets the scalar property with the given name, or does nothing if no such property exists. Gets the number of frames in the animation. Gets the frame rate of the animation. Gets the duration of the animation. Converts a zero-based frame number to the corresponding progress value denoting the start of the frame. Returns a map from marker names to corresponding progress values. Sets the color property with the given name, or does nothing if no such property exists. Sets the scalar property with the given name, or does nothing if no such property exists. Represents a phone request for clipboard operations, handling transfer of clipboard content including MIME types, text values, and image data to the connected phone device. Initializes a new instance of the class. The correlation identifier for tracking this request. The MIME types of the clipboard content. The text values from the clipboard. The image data from the clipboard as byte array. Thrown when correlationId is null. Gets the unique identifier for this request. Gets the correlation identifier for this request. Builds the request message as a ValueSet containing all clipboard data. A ValueSet containing the clipboard request data. Gets the headers for this request. An empty map view as no headers are required for clipboard requests. Represents a phone request for phone apps operations, handling requests for app information such as favorite apps or currently running apps on the connected phone device. Initializes a new instance of the class. The correlation identifier for tracking this request. The type of phone apps request. Initializes a new instance of the class with phone apps data. The correlation identifier for tracking this request. The type of phone apps request. The list of phone apps to include in the request. Initializes a new instance of the class for internal creation. The correlation identifier. The device data. Gets the unique identifier for this request. Creates a phone apps request with default configuration. The device data for the target device. A new instance. Builds the request message as a ValueSet containing all phone apps request data. A ValueSet containing the phone apps request data. Gets the headers for this request. An empty map view as no headers are required for phone apps requests. Adds a remote feature configuration to the ValueSet. The ValueSet to add the configuration to. The name of the remote feature. The value of the remote feature. Defines the types of phone apps requests that can be made. Note: Only add to the end of this enum! Must stay in sync with the Android and iOS versions. Request for favorite apps. Request for currently running apps. PCAppDataTable manages the pcapp_data table and related queries. Returns all app metadata as a read-only list. Returns app metadata for a given package name. Returns app metadata for a given platform app ID. Inserts or updates a batch of app data entities in a transaction. Maps a row from the database to a PCAppDataEntity. Manages the phone_apps table and related queries. Returns the count of phone apps. Returns all phone apps ordered by name. Returns all favorite phone apps ordered by favorite rank. Returns phone apps for the given package names. Returns phone apps for the given app IDs. Returns a single phone app by package name. Returns a single phone app by app ID. Inserts or updates a batch of phone app entities. Inserts or updates a batch of phone app entities with IDs. Inserts or updates a batch of phone app entities without icons. Deletes phone apps by package names. Deletes phone apps by app IDs. Deletes phone apps where the ETag does not match. Updates the favorite rank for a phone app. Updates favorite ranks for a batch of phone apps. Removes a favorite for a phone app. Removes all favorites. Maps a row from the database to a PhoneAppEntity. Synchronizes the table with the given IDs and checksums. Manages the recent_apps table and related queries. Returns all recent apps with icons, ordered by recent_app_rank. Returns all recent main apps with icons, ordered by recent_app_rank. Returns all recent apps, ordered by recent_app_rank. Returns a recent app by its app_id. Inserts or updates a batch of recent app entities. Deletes recent apps by package names. Deletes recent apps by app IDs. Clears all recent apps. Maps a row from the database to a RecentAppEntity. Synchronizes the table with the given IDs and checksums. Returns all hosted app identities currently stored for . Used by cleanup paths that need to operate on a device other than the currently selected one. Unregisters every hosted app package that was registered for . Used by cleanup paths that need to operate on a device other than the currently selected one (e.g. a device that has just been removed from the store). Avoids the per-package query overhead of calling in a loop -- enumerates the installed packages once and unregisters all matches. InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) InitializeComponent() UnloadObject(DependencyObject) Connect() DisconnectUnloadedObject(int connectionId) GetBindingConnector(int connectionId, object target) Caches the scaled, base64-encoded data URIs of phone-app icons so an icon is only produced once per package/size until that app changes. Cards regenerate on every change; without this cache each rebuild re-decodes, re-scales, transcodes and base64-encodes every app icon, producing large repeated allocations. The cache is shared across every companion-card surface that renders app icons (the app grid and grouped-notification activity). The cache owns its invalidation because it knows when the apps change: it subscribes to the phone-apps-manager and events, whose args carry the ids of the app rows that changed, and evicts only those packages. A package name is stable across icon-content changes, so an app's icon can change without its cache key changing; the id-driven eviction (not the key) is what keeps a changed icon from being served stale, while leaving every unaffected icon cached. Synthetic apps (those not backed by a phone-apps row, e.g. the Link-to-Windows notification stub) report an id of -1; their icons are static, so they are cached by package name but not tracked for id-driven eviction. The Dependency property backing the ViewModel property Gets or sets the viewmodel the chrome binds to. InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) The Dependency property backing the ViewModel property Gets or sets the viewmodel the chrome binds to. InitializeComponent() UnloadObject(DependencyObject) Connect() DisconnectUnloadedObject(int connectionId) GetBindingConnector(int connectionId, object target) The Dependency property backing the ViewModel property Gets or sets the viewmodel the chrome binds to. InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) The Dependency property backing the ViewModel property Gets or sets the viewmodel the chrome binds to. InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) The Dependency property backing the ViewModel property Gets or sets the viewmodel the chrome binds to. The Dependency property backing the PadTitleBar property The Dependency property backing the VerticalContentShift property InitializeComponent() UnloadObject(DependencyObject) Connect() DisconnectUnloadedObject(int connectionId) GetBindingConnector(int connectionId, object target) InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. The default associated with a default instance. The source-generated options associated with this context. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. The default associated with a default instance. The source-generated options associated with this context. InitializeComponent() Connect() GetBindingConnector(int connectionId, object target) Main class for providing metadata for the app or library GetXamlType(Type) GetXamlType(String) GetXmlnsDefinitions() Trigger audio workflow on remoting workflow start instead of inside Orchestrator since remoting workflow is the "main" workflow Manages volume of audio during app remoting Audio Streaming Returns the last saved volume for from the database. Set volume slider and mute status for all windows under , send the new volume to the phone, and save to the database. Send the last saved volume in the database for , to the phone ConnectionService owns the fundamental connection setup, initializing workflows, and setting up channels Public facing method that takes in handle requests, does handle management, and requests a connection Only one handle for each workflow can be requested at once. N+1 requests will throw InvalidOperationException Name of workflow to start token Create a new connection even if one already exists and connection handle store is empty. The correlation id to track the connection request handle to connection for the workflow This method ensures that only one connection attempt occurs at once All other invocations will wait for the main connection attempt to succeed (or fail) and will adopt that result as well Exception is thrown (and standardized to ConnectionServiceException) if the connection attempt fails or times out Name of workflow to ensure connection Token by caller for cancellation (e.g. cancel via Close) The correlation id to track the connection request Task to wait for a connection attempt to complete Actual logic to form a connection Underyling components throw if the connection attempt fails or times out Name of workflow to attempt connection Correlation ID to pass around and to Android CancellationToken to cancel the operation Task to wait for a connection attempt to complete Optional feature-specific rejection reason returned by the remote side alongside the generic code. Empty when no reason was provided. This object adapts the Nano IClient interface to APC's IClientAdapter interface This gets a client which is already connected and maintains it. It also creates a message channel so communication is possible with the device. The message channel is for the invocation of workflows The client is the first recipient of any new channels created. It also monitors the connection (instability/close) Waits for the client to finish setting up its internal objects Exceptions thrown: - TaskCanceledException - Close is called and current operations will be canceled - OperationCanceledException - Cancellation token passed into WaitForOpenAsync has been canceled The name of the workflow that triggers the waiting for open action Cancellation token Returns when client has finished setting up internal objects Optional feature-specific rejection reason returned by the remote side alongside a generic ScenarioResult (e.g. CanceledDisconnected). Empty when the remote did not specify a reason. This object adapts the Nano IConnect interface to APC's IConnectAdapter interface This gets the local handshake request in InitializeAsync and uses the remote handshake response in OpenAsync Initializes the p2p transport Exceptions thrown: - TaskCanceledException - Close is called and current operations will be canceled - OperationCanceledException - Cancellation token passed into InitializeAsync has been canceled - InvalidOperationException - Invalid call sequence Returns connection string to be sent to peer for handshake Using the peer's connection string, attempts to open a connection with the peer Exceptions thrown: - TaskCanceledException - Close is called and current operations will be canceled - OperationCanceledException - Cancellation token passed into InitializeAsync has been canceled - InvalidOperationException - Invalid call sequence - ConnectionServiceException - DirectConnectionTimedOut, Error, Canceled, Failed (unexpected), RemoteTransportTooOld, RemoteTransportTooNew Peer's connection string The name of the workflow that triggers the openning action Returns client object with open connection Encapsulates the workflow-level message channel. The lifetime of this object is the lifetime of the workflow Gets a value indicating whether the current connection is local. A local connection typically means that the connected device is on the same local network or within close proximity (e.g., via IP or Wi-Fi Direct), whereas a non-local connection indicates that the device is accessed over a wider network, such as the internet. Initializes and opens the workflow message channel without cancellation token (legacy solution) Throws OperationCanceledException if canceled Throws InvalidOperationException if Open is called incorrectly Task completed on Open success Initializes and opens the workflow message channel with cancellation token (platform solution) Throws InvalidOperationException if Open is called incorrectly Task completed on Open success Encapsulates logic to start a workflow Starts a workflow asynchronously WorkflowException may be fired for unexpected code issues, cancellations, or connection failures Name of workflow to start Opportunity to register listeners with the workflow message channel before open Cancel token to stop the connection while its still starting Name of activity to start Whether to force a new connection Optional message channel type override. WorkflowMessageChannel to represent the workflow connection Updates all rows with an empty device_id to the currently selected device. Called once after database initialization to migrate data from pre-v9 schema. Returns every hosted app identity stored for . Used by cleanup paths that need to operate on a device other than the currently selected one (e.g. a device that has just been removed from the store). Returns the hosted app identity for on the currently selected device, inserting a new row if one does not yet exist for that device. Returns every hosted app identity stored for . Used by cleanup paths that need to operate on a device other than the currently selected one. Get last volume level that was saved in the database for Save in the database as the latest volume level Get last mute state that was saved in the database for Save in the database as the latest mute state Get the last screen layout for the given Save the for the given Used as a Stream by APC, on write of bytes we send them to AP where they are written into the actual Stream Provisions a messaging platform channel early on device connection. If a context handle is already available for the device, channel provisioning is triggered immediately. Otherwise, waits for a context handle to be published before triggering. Each new call cancels any pending wait from a prior call. Ensures the device (PL↔LTW) connection for the supplied device is established before subsequent operations that depend on it, e.g. platform channel creation. If the connectivity state is not Connected, invalidates any cached platform channel for that device, drives a reconnect, and re-verifies the state before returning. Returns successfully if is already connected. Otherwise invalidates the cached platform channel for this device and triggers a reconnect. Throws with reason LostConnection if the reconnect does not bring the state to Connected. Callers are expected to be sequenced (typically via each flow manager's per-instance ISingleRun) so concurrent invocations for the same device are rare. The gate does not deduplicate concurrent reconnect attempts; if N callers race through the disconnected branch, N ConnectAsync requests will be sent. If a future entry point can fan out concurrently without outer sequencing, add a per-device in-flight Task cache here. Ensures a messaging platform channel is available for the specified . Callers are expected to snapshot the deviceId once up front and pass it here so the decision is made against a stable device identity, not a re-read of the global selected-device state. Invalidates any cached platform channel for so the next call recreates it. Used when the underlying PL connection has been lost without propagating ChannelClosed (e.g., user-initiated Disconnect in LTW). If the cached channel is for a different device, the call is a no-op. Retires this workflow channel instance when the factory resets without disposing the underlying messaging platform channel, then detaches all event handlers so the reused platform channel stays clean for the next session. Singleton store for the persistent used across phone-mirroring workflow sessions. Lifetime semantics: - If channel creation is already in progress, returns the same in-flight to every concurrent caller. - If a valid channel already exists for the currently selected device (created but not yet opened, or currently open), it is returned immediately without starting a new creation. - Otherwise a new creation is started and its task is stored for sharing. The channel is intentionally persistent and must not be explicitly closed or disposed by callers. When the channel is opened and subsequently closed, clears the stored task and disposes the channel so the next call starts a fresh creation. Ensures a messaging platform channel is available for the specified . Stable device identifier snapshotted by the caller. Token used only when a new channel creation is initiated; ignored for shared in-flight or cached tasks. Schedules disposal of the channel produced by an in-flight creation task whose owner is abandoning the reference. Also attaches a faulted-only continuation so the task's exception is observed and does not surface as an UnobservedTaskException. Remoting session describes the time while the user is remoting into the phone This interface represents lifecycle events of the remoting workflow Called when the remoting session is starting and objects are initialized for the session Contains objects associated with a new start of the session Called when the remoting session has started Called when the remoting session has stopped Service interface for the lifecycle events of AppProxyConnection Called when the remoting session is starting and objects are initialized for the session Must be cautious about blocking calls as this is called during initialization of the module Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. The default associated with a default instance. The source-generated options associated with this context. Asks Android to check the permission status type of permission to check cancellation token Returns PermissionStatus based on current permission status Asks Android to show permission so user can provide input Its possible that the permission does not show on Android because the permission is disabled type of permission to check cancellation token Returns user input from permission prompt on Android Asks Android to launch app settings so user can change the permission value Returns when the user changes the value, closes the app settings, the request times out, or a new request has been made type of permission to check cancellation token Returns user input from permission prompt on Android Triggers the appropriate audio streaming permission flow based on params provided. Set to null if multiple apps is not supported. IStateMachineWatcher listens for state changes and ensures that the target state machine does not get stuck in an unexpected state. Initialize the watcher with a target state machine. Target state machine Command to be issued if the state machine spends longer than the in an invalid state. Command details to be sent to the state machine if the timeout is reached Maximum time without any transition out of an invalid state. Exceeding the delay causes the watcher to timeout and issue the List of states which are not valid long running states. Exceeding the while in one of theses states will cause a timeout Defines the source generated JSON serialization contract metadata for a given type. Defines the source generated JSON serialization contract metadata for a given type. The default associated with a default instance. The source-generated options associated with this context. This helps coordinate the request and response of messages where the request is fire and forget and a response comes another way. The relationship between the two messages is a transaction id. This helps connect the two together so the caller can expose an async method. This starts a transaction and returns a Task that can be waited on for transaction compmletion. AsyncTransaction that allows the caller to wait and get the transaction id This completes the transaction. The task returned when the transaction was started is completed. Unique id that links to the start of the transaction Value to return in the transaction Supported is whether phone supports audio Enabled is whether PC has EXP enabled whether audio code can run Holds the peer connection type for the current live nano connection so it can be attached to per-launch telemetry. The value is cached when the nano connection is established and cleared when it closes, covering both the platform nano and legacy native nano solutions. The establishing connection owner (the platform messaging channel store or the native connection service) is the sole writer, so at most one owner mutates the value at a time. Gets the peer connection type for the current connection, or when no connection is established or the type is unknown. Caches the peer connection type derived from the connection's local-connection state. A value is treated as unknown and leaves the cached value unchanged. Clears the cached peer connection type when the nano connection closes. This class is used to ensure that a single method will run just once However, it may run again if the method throws or the object is Reset One example of this class's use if there is a method that creates a connection. If there are multiple calls to create that connection from different sources, then only one thread should actually create the connection, while the other threads wait for that thread's completion before continuing This class is thread safe Returns the current run task so callers can check status without invoking a run Returns null if there is no current task Runs the single method if not yet run, or waits for a previous call to complete and returns on completion Returns a task to wait for completion Resets the object so that runs are canceled and threads are released Refreshes the cached CDEH minimum-version compatibility read by . The cached value is optimistic by default, so this refresh only demotes it (to fall back to the legacy solution) when an incompatible CDEH is detected. The package enumeration runs on a threadpool thread, so a caller awaiting this from the UI thread only schedules the work and is released at the await; the UI thread is never blocked by the enumeration. Concurrent calls are coalesced: if a refresh is already in flight, the call is skipped since the in-flight run already reads the latest package state. Describes a pointer. Learn more about this API from docs.microsoft.com. Pointer to a function. Pointer to a variable, constant, or data member. The ITypeComp that binds the pointer. The BLOB structure (nspapi.h), which is derived from Binary Large Object, contains information about a block of data. The structure name BLOB comes from the acronym BLOB, which stands for Binary Large Object. This structure does not describe the nature of the data pointed to by pBlobData.
Note  Windows Sockets defines a similar BLOB structure in Wtypes.h. Using both header files in the same source code file creates redefinition–compile time errors.
 
 Read more on docs.microsoft.com. Size of the block of data pointed to by pBlobData, in bytes. Pointer to a block of data. Retrieves a specified number of STATSTG structures, that follow in the enumeration sequence. The number of STATSTG structures requested. An array of STATSTG structures returned. The number of STATSTG structures retrieved in the rgelt parameter. This method supports the following return values: This doc was truncated. Learn more about this API from docs.microsoft.com. Skips a specified number of STATSTG structures in the enumeration sequence. The number of STATSTG structures to skip. This method supports the following return values: | Return code | Description | |----------------|---------------| | S_OK | The specified number of **STATSTG** structures that were successfully skipped. | | S_FALSE | The number of **STATSTG** structures skipped is less than the *celt* parameter. | Learn more about this API from docs.microsoft.com. Resets the enumeration sequence to the beginning of the STATSTG structure array. This method supports the S_OK return value. This doc was truncated. Learn more about this API from docs.microsoft.com. Creates a new enumerator that contains the same enumeration state as the current STATSTG structure enumerator. A pointer to the variable that receives the IEnumSTATSTG interface pointer. If the method is unsuccessful, the value of the ppenum parameter is undefined. Read more on docs.microsoft.com. This method supports the following return values. This doc was truncated. Learn more about this API from docs.microsoft.com. The IID guid for this interface. {0000000d-0000-0000-c000-000000000046} Creates and opens a stream object with the specified name contained in this storage object. A pointer to a wide character null-terminated Unicode string that contains the name of the newly created stream. The name can be used later to open or reopen the stream. The name must not exceed 31 characters in length, not including the string terminator. The 000 through 01f characters, serving as the first character of the stream/storage name, are reserved for use by OLE. This is a compound file restriction, not a structured storage restriction. Specifies the access mode to use when opening the newly created stream. For more information and descriptions of the possible values, see STGM Constants. Reserved for future use; must be zero. Reserved for future use; must be zero. On return, pointer to the location of the new IStream interface pointer. This is only valid if the operation is successful. When an error occurs, this parameter is set to NULL. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The new stream was successfully created.| |E_PENDING | Asynchronous Storage only: Part or all of the necessary data is currently unavailable. | |STG_E_ACCESSDENIED | Not enough permissions to create stream.| |STG_E_FILEALREADYEXISTS | The name specified for the stream already exists in the storage object and the *grfMode* parameter includes the value STGM_FAILIFTHERE.| |STG_E_INSUFFICIENTMEMORY | The stream was not created due to a lack of memory.| |STG_E_INVALIDFLAG | The value specified for the *grfMode* parameter is not a valid **STGM** constants value.| |STG_E_INVALIDFUNCTION | The specified combination of flags in the *grfMode* parameter is not supported; for example, when this method is called without the STGM_SHARE_EXCLUSIVE flag.| |STG_E_INVALIDNAME | Invalid value for *pwcsName*.| |STG_E_INVALIDPOINTER | The pointer specified for the stream object was invalid.| |STG_E_INVALIDPARAMETER | One of the parameters was invalid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_TOOMANYOPENFILES | The stream was not created because there are too many open files.| If a stream with the name specified in the pwcsName parameter already exists and the grfMode parameter includes the STGM_CREATE flag, the existing stream is replaced by a newly created one. Both the destruction of the old stream and the creation of the new stream object are subject to the transaction mode on the parent storage object. The COM-provided compound file implementation of the IStorage::CreateStream method does not support the following behaviors: This doc was truncated. Read more on docs.microsoft.com. Opens an existing stream object within this storage object in the specified access mode. A pointer to a wide character null-terminated Unicode string that contains the name of the stream to open. The 000 through 01f characters, serving as the first character of the stream/storage name, are reserved for use by OLE. This is a compound file restriction, not a structured storage restriction. Reserved for future use; must be NULL. Specifies the access mode to be assigned to the open stream. For more information and descriptions of possible values, see STGM Constants. Other modes you choose must at least specify STGM_SHARE_EXCLUSIVE when calling this method in the compound file implementation. Reserved for future use; must be zero. A pointer to IStream pointer variable that receives the interface pointer to the newly opened stream object. If an error occurs, *ppstm must be set to NULL. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The stream was successfully opened.| |E_PENDING | Asynchronous Storage only: Part or all of the stream data is currently unavailable. | |STG_E_ACCESSDENIED | Not enough permissions to open stream.| |STG_E_FILENOTFOUND | The stream with specified name does not exist.| |STG_E_INSUFFICIENTMEMORY | The stream was not opened due to a lack of memory.| |STG_E_INVALIDFLAG | The value specified for the *grfMode* parameter is not a valid **STGM** constants value.| |STG_E_INVALIDFUNCTION | The specified combination of flags in the *grfMode* parameter is not supported; for example, when this method is called without the STGM_SHARE_EXCLUSIVE flag.| |STG_E_INVALIDNAME | Invalid value for *pwcsName*.| |STG_E_INVALIDPOINTER | The pointer specified for the stream object was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_TOOMANYOPENFILES | The stream was not opened because there are too many open files.| IStorage::OpenStream opens an existing stream object within this storage object in the access mode specified in grfMode. There are restrictions on the permissions that can be given in grfMode. For example, the permissions on this storage object restrict the permissions on its streams. In general, access restrictions on streams need to be stricter than those on their parent storages. Compound-file streams must be opened with STGM_SHARE_EXCLUSIVE. Opens an existing storage object with the specified name in the specified access mode. A pointer to a wide character null-terminated Unicode string that contains the name of the storage object to open. The 000 through 01f characters, serving as the first character of the stream/storage name, are reserved for use by OLE. This is a compound file restriction, not a structured storage restriction. It is ignored if pstgPriority is non-NULL. Must be NULL. A non-NULL value will return STG_E_INVALIDPARAMETER. Specifies the access mode to use when opening the storage object. For descriptions of the possible values, see STGM Constants. Other modes you choose must at least specify STGM_SHARE_EXCLUSIVE when calling this method. Must be NULL. A non-NULL value will return STG_E_INVALIDPARAMETER. Reserved for future use; must be zero. When successful, pointer to the location of an IStorage pointer to the opened storage object. This parameter is set to NULL if an error occurs. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The storage object was opened successfully.| |E_PENDING | Asynchronous Storage only: Part or all of the storage's data is currently unavailable. | |STG_E_ACCESSDENIED | Not enough permissions to open storage object.| |STG_E_FILENOTFOUND | The storage object with the specified name does not exist.| |STG_E_INSUFFICIENTMEMORY | The storage object was not opened due to a lack of memory.| |STG_E_INVALIDFLAG | The value specified for the *grfMode* parameter is not a valid **STGM** constants value.| |STG_E_INVALIDFUNCTION | The specified combination of flags in the *grfMode* parameter is not supported.| |STG_E_INVALIDNAME | Not a valid value for *pwcsName*.| |STG_E_INVALIDPOINTER | The pointer specified for the storage object was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_TOOMANYOPENFILES | The storage object was not created because there are too many open files.| |STG_S_CONVERTED | The existing stream with the specified name was replaced with a new storage object containing a single stream called CONTENTS. In direct mode, the new storage is immediately written to disk. In transacted mode, the new storage is written to a temporary storage in memory and later written to disk when it is committed.| If the pstgPriority parameter is NULL, it is ignored. If the pstgPriority parameter is not NULL, it is an IStorage pointer to a previous opening of an element of the storage object, usually one that was opened in priority mode. The storage object should be closed and reopened according to grfMode. When the IStorage::OpenStorage method returns, pstgPriority is no longer valid. Use the value supplied in the ppstg parameter. Storage objects can be opened with STGM_DELETEONRELEASE, in which case the object is destroyed when it receives its final release. This is useful for creating temporary storage objects. Read more on docs.microsoft.com. Copies the entire contents of an open storage object to another storage object. The number of elements in the array pointed to by rgiidExclude. If rgiidExclude is NULL, then ciidExclude is ignored. An array of interface identifiers (IIDs) that either the caller knows about and does not want copied or that the storage object does not support, but whose state the caller will later explicitly copy. The array can include IStorage, indicating that only stream objects are to be copied, and IStream, indicating that only storage objects are to be copied. An array length of zero indicates that only the state exposed by the IStorage object is to be copied; all other interfaces on the object are to be ignored. Passing NULL indicates that all interfaces on the object are to be copied. Read more on docs.microsoft.com. A string name block (refer to SNB) that specifies a block of storage or stream objects that are not to be copied to the destination. These elements are not created at the destination. If IID_IStorage is in the rgiidExclude array, this parameter is ignored. This parameter may be NULL. Read more on docs.microsoft.com. A pointer to the open storage object into which this storage object is to be copied. The destination storage object can be a different implementation of the IStorage interface from the source storage object. Thus, IStorage::CopyTo can use only publicly available methods of the destination storage object. If pstgDest is open in transacted mode, it can be reverted by calling its IStorage::Revert method. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The storage object was successfully copied.| |E_PENDING | Asynchronous Storage only: Part or all of the data to be copied is currently unavailable. | |STG_E_ACCESSDENIED | The destination storage object is a child of the source storage object.| |STG_E_INSUFFICIENTMEMORY | The copy was not completed due to a lack of memory.| |STG_E_INVALIDPOINTER | The pointer specified for the storage object was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_TOOMANYOPENFILES | The copy was not completed because there are too many open files.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_MEDIUMFULL | The copy was not completed because the storage medium is full.| This method merges elements contained in the source storage object with those already present in the destination. The layout of the destination storage object may differ from the source storage object. The copy process is recursive, invoking IStorage::CopyTo and IStream::CopyTo on the elements nested inside the source. When copying a stream on top of an existing stream with the same name, the existing stream is first removed and then replaced with the source stream. When copying a storage on top of an existing storage with the same name, the existing storage is not removed. As a result, after the copy operation, the destination IStorage contains older elements, unless they were replaced by newer ones with the same names. A storage object may expose interfaces other than IStorage, including IRootStorage, IPropertyStorage, or IPropertySetStorage. The rgiidExclude parameter permits the exclusion of any or all of these additional interfaces from the copy operation. A caller with a newer or more efficient copy of an existing substorage or stream object may want to exclude the current versions of these objects from the copy operation. The snbExclude and rgiidExclude parameters provide two ways of excluding a storage objects existing storages or streams.

Note to Callers

The most common way to use the IStorage::CopyTo method is to copy everything from the source to the destination, as in most full-save and save-as operations. The following example code shows how to copy everything from the source storage object to the destination storage object. This doc was truncated. Read more on docs.microsoft.com. The MoveElementTo method copies or moves a substorage or stream from this storage object to another storage object. Pointer to a wide character null-terminated Unicode string that contains the name of the element in this storage object to be moved or copied. IStorage pointer to the destination storage object. Pointer to a wide character null-terminated unicode string that contains the new name for the element in its new storage object. Specifies whether the operation should be a move (STGMOVE_MOVE) or a copy (STGMOVE_COPY). See the STGMOVE enumeration. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The storage object was successfully copied or moved.| |E_PENDING | Asynchronous Storage only: Part or all of the element's data is currently unavailable. | |STG_E_ACCESSDENIED | The destination storage object is a child of the source storage object. Or, the destination object and element name are the same as the source object and element name. In other words, you cannot move an element to itself.| |STG_E_FILENOTFOUND | The element with the specified name does not exist.| |STG_E_FILEALREADYEXISTS | The specified file already exists.| |STG_E_INSUFFICIENTMEMORY | The copy or move was not completed due to a lack of memory.| |STG_E_INVALIDFLAG | The value for the *grfFlags* parameter is not valid.| |STG_E_INVALIDNAME | Not a valid value for *pwcsName*.| |STG_E_INVALIDPOINTER | The pointer specified for the storage object was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_TOOMANYOPENFILES | The copy or move was not completed because there are too many open files.| The IStorage::MoveElementTo method is typically the same as invoking the IStorage::CopyTo method on the indicated element and then removing the source element. In this case, the MoveElementTo method uses only the publicly available functions of the destination storage object to carry out the move. If the source and destination storage objects have special knowledge about each other's implementation (they could, for example, be different instances of the same implementation), this method can be implemented more efficiently. Before calling this method, the element to be moved must be closed, and the destination storage must be open. Also, the destination object and element cannot be the same storage object/element name as the source of the move. That is, you cannot move an element to itself. Read more on docs.microsoft.com. The Commit method ensures that any changes made to a storage object open in transacted mode are reflected in the parent storage. Controls how the changes are committed to the storage object. See the STGC enumeration for a definition of these values. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | Changes to the storage object were successfully committed to the parent level. If STGC_CONSOLIDATE was specified, the storage was successfully consolidated, or the storage was already too compact to consolidate further.| |STG_S_MULTIPLEOPENS | The commit operation succeeded, but the storage could not be consolidated because it had been opened multiple times using the STGM_NOSNAPSHOT flag.| |STG_S_CANNOTCONSOLIDATE | The commit operation succeeded, but the storage could not be consolidated due to an incorrect storage mode. For compound files, the storage may have been opened using the STGM_NOSCRATCH flag, or the storage may not be the outermost transacted level.| |STG_S_CONSOLIDATIONFAILED | The commit operation succeeded, but the storage could not be consolidated due to an internal error (for example, a memory allocation failure).| |E_PENDING | Asynchronous storage only: Part or all of the data to be committed is currently unavailable.| |STG_E_INVALIDFLAG | The value for the *grfCommitFlags* parameter is not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_NOTCURRENT | Another open instance of the storage object has committed changes. As a result, the current commit operation may overwrite previous changes.| |STG_E_MEDIUMFULL | No space left on device to commit.| |STG_E_TOOMANYOPENFILES | The commit operation could not be completed because there are too many open files.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| IStorage::Commit makes permanent changes to a storage object that is in transacted mode, in which changes are accumulated in a buffer, and not reflected in the storage object until there is a call to this method. The alternative is to open an object in direct mode, in which changes are immediately reflected in the storage object. An object opened in the direct mode does not require calling IStorage::Commit to make permanent changes in the storage object. Calling the IStorage::Commit method on a nonroot storage opened in direct mode has no effect. Opening a root storage object in direct mode ensures that changes in memory buffers are written to the underlying storage device. The commit operation publishes the current changes in this storage object and its children to the next level up in the storage hierarchy. To undo current changes before committing them, call IStorage::Revert to roll back to the last-committed version. Calling IStorage::Commit has no effect on currently opened nested elements of this storage object. They remain valid and can be used. However, the IStorage::Commit method does not automatically commit changes to these nested elements. The commit operation publishes only known changes to the next higher level in the storage hierarchy. Thus, transactions to nested levels must be committed to this storage object before they can be committed to higher levels. In commit operations, you need to take steps to ensure that data is protected during the commit process: This doc was truncated. Read more on docs.microsoft.com. The Revert method discards all changes that have been made to the storage object since the last commit operation. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The revert operation was successful.| |E_PENDING | Asynchronous Storage only: Part or all of the storage's data is currently unavailable. | |STG_E_INSUFFICIENTMEMORY | The revert operation could not be completed due to a lack of memory.| |STG_E_TOOMANYOPENFILES | The revert operation could not be completed because there are too many open files.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| For storage objects opened in transacted mode, the IStorage::Revert method discards any uncommitted changes to this storage object or changes that have been committed to this storage object from nested elements. After this method returns, any existing elements (substorages or streams) that were opened from the reverted storage object are invalid and can no longer be used. Specifying these reverted elements in any call except IUnknown::Release returns the error STG_E_REVERTED This method has no effect on storage objects opened in direct mode. Read more on docs.microsoft.com. The EnumElements method retrieves a pointer to an enumerator object that can be used to enumerate the storage and stream objects contained within this storage object. Reserved for future use; must be zero. Reserved for future use; must be NULL. Reserved for future use; must be zero. Pointer to IEnumSTATSTG* pointer variable that receives the interface pointer to the new enumerator object. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The enumerator object was successfully returned.| |E_PENDING | Asynchronous Storage only: Part or all of the element's data is currently unavailable.| |STG_E_INSUFFICIENTMEMORY | The enumerator object could not be created due to lack of memory.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| The enumerator object returned by this method implements the IEnumSTATSTG interface, one of the standard enumerator interfaces that contain the Next, Reset, Clone, and Skip methods. IEnumSTATSTG enumerates the data stored in an array of STATSTG structures. The storage object must be open in read mode to allow the enumeration of its elements. The enumerator object is permitted to enumerate the elements in any order. The enumerator object is also permitted to treat the enumeration as a snapshot or to have the enumeration reflect the current state of the storage object. Read more on docs.microsoft.com. The RenameElement method renames the specified substorage or stream in this storage object. Pointer to a wide character null-terminated Unicode string that contains the name of the substorage or stream to be changed.
Note  The pwcsName, created in CreateStorage or CreateStream must not exceed 31 characters in length, not including the string terminator.
 
 Read more on docs.microsoft.com. Pointer to a wide character null-terminated unicode string that contains the new name for the specified substorage or stream.
Note  The pwcsName, created in CreateStorage or CreateStream must not exceed 31 characters in length, not including the string terminator.
 
 Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The element was successfully renamed.| |E_PENDING | Asynchronous Storage only: Part or all of the element's data is currently unavailable.| |STG_E_ACCESSDENIED | The caller does not have enough permissions for renaming the element.| |STG_E_FILENOTFOUND | The element with the specified old name does not exist.| |STG_E_FILEALREADYEXISTS | The element specified by the new name already exists.| |STG_E_INSUFFICIENTMEMORY | The element was not renamed due to a lack of memory.| |STG_E_INVALIDNAME | Invalid value for one of the names.| |STG_E_INVALIDPOINTER | The pointer specified for the element was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_TOOMANYOPENFILES | The element was not renamed because there are too many open files.| IStorage::RenameElement renames the specified substorage or stream in this storage object. An element in a storage object cannot be renamed while it is open. The rename operation is subject to committing the changes if the storage is open in transacted mode. The IStorage::RenameElement method is not guaranteed to work in low memory with storage objects open in transacted mode. It may work in direct mode. Read more on docs.microsoft.com. The SetElementTimes method sets the modification, access, and creation times of the specified storage element, if the underlying file system supports this method. The name of the storage object element whose times are to be modified. If NULL, the time is set on the root storage rather than one of its elements. Either the new creation time for the element or NULL if the creation time is not to be modified. Either the new access time for the element or NULL if the access time is not to be modified. Either the new modification time for the element or NULL if the modification time is not to be modified. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The time values were successfully set.| |E_PENDING | Asynchronous Storage only: Part or all of the element's data is currently unavailable.| |STG_E_ACCESSDENIED | The caller does not have enough permissions for changing the element.| |STG_E_FILENOTFOUND | The element with the specified name does not exist.| |STG_E_INSUFFICIENTMEMORY | The element was not changed due to a lack of memory.| |STG_E_INVALIDNAME | Not a valid value for the element name.| |STG_E_INVALIDPOINTER | The pointer specified for the element was not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| |STG_E_TOOMANYOPENFILES | The element was not changed because there are too many open files.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| SetElementTimes sets time statistics for the specified storage element within this storage object. Not all file systems support all the time values. This method sets those times that are supported and ignores the rest. Each time-value parameter can be NULL; indicating that no modification should occur. Call the IStorage::Stat method to retrieve these time values. Read more on docs.microsoft.com. The SetClass method assigns the specified class identifier (CLSID) to this storage object. The CLSID that is to be associated with the storage object. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The CLSID was successfully assigned.| |E_PENDING | Asynchronous Storage only: Part or all of the storage's data is currently unavailable.| |STG_E_ACCESSDENIED | The caller does not have enough permissions for assigning a CLSID to the storage object.| |STG_E_MEDIUMFULL | Not enough space was left on device to complete the operation.| |STG_E_REVERTED | The storage object has been invalidated by a revert operation above it in the transaction tree.| When first created, a storage object has an associated CLSID of CLSID_NULL. Call SetClass to assign a CLSID to the storage object. Call the IStorage::Stat method to retrieve the current CLSID of a storage object. Read more on docs.microsoft.com. The SetStateBits method stores up to 32 bits of state information in this storage object. Specifies the new values of the bits to set. No legal values are defined for these bits; they are all reserved for future use and must not be used by applications. A binary mask indicating which bits in grfStateBits are significant in this call. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The state information was successfully set.| |E_PENDING | Asynchronous Storage only: Part or all of the storage's data is currently unavailable. | |STG_E_ACCESSDENIED | The caller does not have enough permissions for changing this storage object.| |STG_E_INVALIDFLAG | The value for the grfStateBits or *grfMask* parameter is not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| The values for the state bits are not currently defined. The Stat method retrieves the STATSTG structure for this open storage object. On return, pointer to a STATSTG structure where this method places information about the open storage object. This parameter is NULL if an error occurs. Read more on docs.microsoft.com. Specifies that some of the members in the STATSTG structure are not returned, thus saving a memory allocation operation. Values are taken from the STATFLAG enumeration. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The STATSTG structure was successfully returned at the specified location.| |E_PENDING | Asynchronous Storage only: Part or all of the storage's data is currently unavailable.| |STG_E_ACCESSDENIED | The caller does not have enough permissions for accessing statistics for this storage object.| |STG_E_INSUFFICIENTMEMORY | The STATSTG structure was not returned due to a lack of memory.| |STG_E_INVALIDFLAG | The value for the *grfStateFlag* parameter is not valid.| |STG_E_INVALIDPARAMETER | One of the parameters was not valid.| IStorage::Stat retrieves the STATSTG structure for the current storage object. The STATSTG structure contains statistical information about the storage object. IStorage::EnumElements returns a pointer to an enumerator object. The enumerator object returned by this method implements the IEnumSTATSTG interface, through which the data stored in the array of the STATSTG structures is enumerated. Read more on docs.microsoft.com. The IID guid for this interface. {0000000b-0000-0000-c000-000000000046} The PROPVARIANT structure is used in the ReadMultiple and WriteMultiple methods of IPropertyStorage to define the type tag and the value of a property in a property set. The PROPVARIANT structure can also hold a value of VT_DECIMAL: This doc was truncated. Read more on docs.microsoft.com. Identifies the calling convention used by a member function described in the METHODDATA structure. Learn more about this API from docs.microsoft.com. The CY structure is useful for calculations involving money, or for any fixed-point calculation where accuracy is particularly important. Identifies the type description being bound to. Learn more about this API from docs.microsoft.com. No match was found. A FUNCDESC was returned. A VARDESC was returned. A TYPECOMP was returned. An IMPLICITAPPOBJ was returned. The end of the enum. Contains the arguments passed to a method or property. Learn more about this API from docs.microsoft.com. An array of arguments. **Note**: these arguments appear in reverse order Read more on docs.microsoft.com. The dispatch IDs of the named arguments. The number of arguments. The number of named arguments. The ELEMDESC structure contains the type description and process-transfer information for a variable, a function, or a function parameter. (ELEMDESC) The type of the element. Describes an exception that occurred during IDispatch::Invoke. Use the pfnDeferredFillIn field to enable an object to defer filling in the bstrDescription, bstrHelpFile, and dwHelpContext fields until they are needed. This field might be used, for example, if loading the string for the error is a time-consuming operation. To use deferred fill-in, the object puts a function pointer in this slot and does not fill any of the other fields except wCode, which is required. To get additional information, the caller passes the EXCEPINFO structure back to the pexcepinfo callback function, which fills in the additional information. When the ActiveX object and the ActiveX client are in different processes, the ActiveX object calls pfnDeferredFillIn before returning to the controller. Read more on docs.microsoft.com. The error code. Error codes should be greater than 1000. Either this field or the scode field must be filled in; the other must be set to 0. Reserved. Should be 0. The name of the exception source. Typically, this is an application name. This field should be filled in by the implementer of IDispatch. The exception description to display. If no description is available, use null. The fully qualified help file path. If no Help is available, use null. The help context ID. Reserved. Must be null. Provides deferred fill-in. If deferred fill-in is not desired, this field should be set to null. A return value that describes the error. Either this field or wCode (but not both) must be filled in; the other must be set to 0. (16-bit Windows versions only.) Describes a function. (FUNCDESC) The cParams field specifies the total number of required and optional parameters. The cParamsOpt field specifies the form of optional parameters accepted by the function, as follows: This doc was truncated. Read more on docs.microsoft.com. The function member ID. The status code. Description of the element. Indicates the type of function (virtual, static, or dispatch-only). The invocation type. Indicates whether this is a property function, and if so, which type. The calling convention. The total number of parameters. The number of optional parameters. For FUNC_VIRTUAL, specifies the offset in the VTBL. The number of possible return values. The function return type. The function flags. See FUNCFLAGS. Specifies function flags. FUNCFLAG_FHIDDEN means that the property should never be shown in object browsers, property browsers, and so on. This function is useful for removing items from an object model. Code can bind to the member, but the user will never know that the member exists. FUNCFLAG_FNONBROWSABLE means that the property should not be displayed in a properties browser. It is used in circumstances in which an error would occur if the property were shown in a properties browser. FUNCFLAG_FRESRICTED means that macro-oriented programmers should not be allowed to access this member. These members are usually treated as _FHIDDEN by tools such as Visual Basic, with the main difference being that code cannot bind to those members. Read more on docs.microsoft.com. The function should not be accessible from macro languages. This flag is intended for system-level functions or functions that type browsers should not display. The function returns an object that is a source of events. The function that supports data binding. When set, any call to a method that sets the property results first in a call to IPropertyNotifySink::OnRequestEdit. The implementation of OnRequestEdit determines if the call is allowed to set the property. The function that is displayed to the user as bindable. FUNC_FBINDABLE must also be set. The function that best represents the object. Only one function in a type information can have this attribute. The function should not be displayed to the user, although it exists and is bindable. The function supports GetLastError. If an error occurs during the function, the caller can call GetLastError to retrieve the error code. Permits an optimization in which the compiler looks for a member named xyz on the type of abc. If such a member is found and is flagged as an accessor function for an element of the default collection, then a call is generated to that member function. Permitted on members in dispinterfaces and interfaces; not permitted on modules. For more information, refer to defaultcollelem in Type Libraries and the Object Description Language. The type information member is the default member for display in the user interface. The property appears in an object browser, but not in a properties browser. Tags the interface as having default behaviors. Mapped as individual bindable properties. Specifies the function type. Learn more about this API from docs.microsoft.com. The function is accessed the same as PUREVIRTUAL, except the function has an implementation. The function is accessed through the virtual function table (VTBL), and takes an implicit this pointer. The function is accessed by static address and takes an implicit this pointer. The function is accessed by static address and does not take an implicit this pointer. The function can be accessed only through IDispatch. Retrieves the number of type information interfaces that an object provides (either 0 or 1). The number of type information interfaces provided by the object. If the object provides type information, this number is 1; otherwise the number is 0. This method can return one of these values. This doc was truncated. The method may return zero, which indicates that the object does not provide any type information. In this case, the object may still be programmable through IDispatch or a VTBL, but does not provide run-time type information for browsers, compilers, or other programming tools that access type information. This can be useful for hiding an object from browsers. Retrieves the type information for an object, which can then be used to get the type information for an interface. The type information to return. Pass 0 to retrieve type information for the IDispatch implementation. The locale identifier for the type information. An object may be able to return different type information for different languages. This is important for classes that support localized member names. For classes that do not support localized member names, this parameter can be ignored. The requested type information object. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Maps a single member and an optional set of argument names to a corresponding set of integer DISPIDs, which can be used on subsequent calls to Invoke. Reserved for future use. Must be IID_NULL. The array of names to be mapped. The count of the names to be mapped. The locale context in which to interpret the names. Caller-allocated array, each element of which contains an identifier (ID) corresponding to one of the names passed in the rgszNames array. The first element represents the member name. The subsequent elements represent each of the member's parameters. This method can return one of these values. This doc was truncated. An IDispatch implementation can associate any positive integer ID value with a given name. Zero is reserved for the default, or Value property; –1 is reserved to indicate an unknown name; and other negative values are defined for other purposes. For example, if GetIDsOfNames is called, and the implementation does not recognize one or more of the names, it returns DISP_E_UNKNOWNNAME, and the rgDispId array contains DISPID_UNKNOWN for the entries that correspond to the unknown names. The member and parameter DISPIDs must remain constant for the lifetime of the object. This allows a client to obtain the DISPIDs once, and cache them for later use. When GetIDsOfNames is called with more than one name, the first name (rgszNames[0]) corresponds to the member name, and subsequent names correspond to the names of the member's parameters. The same name may map to different DISPIDs, depending on context. For example, a name may have a DISPID when it is used as a member name with a particular interface, a different ID as a member of a different interface, and different mapping for each time it appears as a parameter. GetIDsOfNames is used when an IDispatch client binds to names at run time. To bind at compile time instead, an IDispatch client can map names to DISPIDs by using the type information interfaces described in Type Description Interfaces. This allows a client to bind to members at compile time and avoid calling GetIDsOfNames at run time. For a description of binding at compile time, see Type Description Interfaces. The implementation of GetIDsOfNames is case insensitive. Users that need case-sensitive name mapping should use type information interfaces to map names to DISPIDs, rather than call GetIDsOfNames.
Caution  You cannot use this method to access values that have been added dynamically, such as values added through JavaScript. Instead, use the GetDispID of the IDispatchEx interface. For more information, see the IDispatchEx interface.
 
 Read more on docs.microsoft.com. Provides access to properties and methods exposed by an object. Identifies the member. Use GetIDsOfNames or the object's documentation to obtain the dispatch identifier. Reserved for future use. Must be IID_NULL. The locale context in which to interpret arguments. The lcid is used by the GetIDsOfNames function, and is also passed to Invoke to allow the object to interpret its arguments specific to a locale. Applications that do not support multiple national languages can ignore this parameter. For more information, refer to Supporting Multiple National Languages and Exposing ActiveX Objects. Read more on docs.microsoft.com. Flags describing the context of the Invoke call. This doc was truncated. Read more on docs.microsoft.com. Pointer to a DISPPARAMS structure containing an array of arguments, an array of argument DISPIDs for named arguments, and counts for the number of elements in the arrays. Pointer to the location where the result is to be stored, or NULL if the caller expects no result. This argument is ignored if DISPATCH_PROPERTYPUT or DISPATCH_PROPERTYPUTREF is specified. Pointer to a structure that contains exception information. This structure should be filled in if DISP_E_EXCEPTION is returned. Can be NULL. The index within rgvarg of the first argument that has an error. Arguments are stored in pDispParams->rgvarg in reverse order, so the first argument is the one with the highest index in the array. This parameter is returned only when the resulting return value is DISP_E_TYPEMISMATCH or DISP_E_PARAMNOTFOUND. This argument can be set to null. For details, see Returning Errors. This method can return one of these values. This doc was truncated. Generally, you should not implement Invoke directly. Instead, use the dispatch interface to create functions CreateStdDispatch and DispInvoke. For details, refer to CreateStdDispatch, DispInvoke, Creating the IDispatch Interface and Exposing ActiveX Objects. If some application-specific processing needs to be performed before calling a member, the code should perform the necessary actions, and then call ITypeInfo::Invoke to invoke the member. ITypeInfo::Invoke acts exactly like Invoke. The standard implementations of Invoke created by CreateStdDispatch and DispInvoke defer to ITypeInfo::Invoke. In an ActiveX client, Invoke should be used to get and set the values of properties, or to call a method of an ActiveX object. The dispIdMember argument identifies the member to invoke. The DISPIDs that identify members are defined by the implementer of the object and can be determined by using the object's documentation, the IDispatch::GetIDsOfNames function, or the ITypeInfo interface. When you use IDispatch::Invoke() with DISPATCH_PROPERTYPUT or DISPATCH_PROPERTYPUTREF, you have to specially initialize the cNamedArgs and rgdispidNamedArgs elements of your DISPPARAMS structure with the following: This doc was truncated. Read more on docs.microsoft.com. The IID guid for this interface. {00020400-0000-0000-c000-000000000046} Specifies the way a function is invoked. In C, value assignment is written as *pobj1 = *pobj2, while reference assignment is written as pobj1 = pobj2. Other languages have other syntactic conventions. A property or data member can support only a value assignment, a reference assignment, or both. The INVOKEKIND enumeration constants are the same constants that are passed to IDispatch::Invoke to specify the way in which a function is invoked. The member is called using a normal function invocation syntax. The function is invoked using a normal property-access syntax. The function is invoked using a property value assignment syntax. Syntactically, a typical programming language might represent changing a property in the same way as assignment. For example: object.property : = value. The function is invoked using a property reference assignment syntax. Reads a specified number of bytes from the stream object into memory, starting at the current seek pointer. A pointer to the buffer which the stream data is read into. The number of bytes of data to read from the stream object. A pointer to a ULONG variable that receives the actual number of bytes read from the stream object.
Note  The number of bytes read may be zero.
 
 Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | All of the requested data was successfully read from the stream object; the number of bytes requested in *cb* is the same as the number of bytes returned in *pcbRead*.| |S_FALSE | The value returned in *pcbRead* is less than the number of bytes requested in *cb*. This indicates the end of the stream has been reached. The number of bytes read indicates how much of the *pv* buffer has been filled.| |E_PENDING | Asynchronous storage only: Part or all of the data to be read is currently unavailable. | |STG_E_ACCESSDENIED | The caller does not have permissions required to read this stream object.| |STG_E_INVALIDPOINTER | One of the pointer values is invalid.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| This method reads bytes from this stream object into memory. The stream object must be opened in STGM_READ mode. This method adjusts the seek pointer by the actual number of bytes read. The number of bytes actually read is also returned in the pcbRead parameter.

Notes to Callers

The actual number of bytes read can be less than the number of bytes requested if an error occurs or if the end of the stream is reached during the read operation. The number of bytes returned should always be compared to the number of bytes requested. If the number of bytes returned is less than the number of bytes requested, it usually means the Read method attempted to read past the end of the stream. The application should handle both a returned error and S_OK return values on end-of-stream read operations. Read more on docs.microsoft.com. Writes a specified number of bytes into the stream object starting at the current seek pointer. A pointer to the buffer that contains the data that is to be written to the stream. A valid pointer must be provided for this parameter even when cb is zero. The number of bytes of data to attempt to write into the stream. This value can be zero. A pointer to a ULONG variable where this method writes the actual number of bytes written to the stream object. The caller can set this pointer to NULL, in which case this method does not provide the actual number of bytes written. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The data was successfully written to the stream object.| |E_PENDING | Asynchronous Storage only: Part or all of the data to be written is currently unavailable.| |STG_E_MEDIUMFULL | The write operation failed because there is no space left on the storage device.| |STG_E_ACCESSDENIED | The caller does not have the required permissions for writing to this stream object.| |STG_E_CANTSAVE | Data cannot be written for reasons other than improper access or insufficient space.| |STG_E_INVALIDPOINTER | One of the pointer values is not valid. The *pv* parameter must contain a valid pointer even if *cb* is zero.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| |STG_E_WRITEFAULT | The write operation failed due to a disk error. This value is also returned when this method attempts to write to a stream that was opened in simple mode (using the STGM_SIMPLE flag).| ISequentialStream::Write writes the specified data to a stream object. The seek pointer is adjusted for the number of bytes actually written. The number of bytes actually written is returned in the pcbWritten parameter. If the byte count is zero bytes, the write operation has no effect. If the seek pointer is currently past the end of the stream and the byte count is nonzero, this method increases the size of the stream to the seek pointer and writes the specified bytes starting at the seek pointer. The fill bytes written to the stream are not initialized to any particular value. This is the same as the end-of-file behavior in the MS-DOS FAT file system. With a zero byte count and a seek pointer past the end of the stream, this method does not create the fill bytes to increase the stream to the seek pointer. In this case, you must call the IStream::SetSize method to increase the size of the stream and write the fill bytes. The pcbWritten parameter can have a value even if an error occurs. In the COM-provided implementation, stream objects are not sparse. Any fill bytes are eventually allocated on the disk and assigned to the stream. Read more on docs.microsoft.com. The IID guid for this interface. {0c733a30-2a1c-11ce-ade5-00aa0044773d} Changes the seek pointer to a new location. The new location is relative to either the beginning of the stream, the end of the stream, or the current seek pointer. The displacement to be added to the location indicated by the dwOrigin parameter. If dwOrigin is STREAM_SEEK_SET, this is interpreted as an unsigned value rather than a signed value. The origin for the displacement specified in dlibMove. The origin can be the beginning of the file (STREAM_SEEK_SET), the current seek pointer (STREAM_SEEK_CUR), or the end of the file (STREAM_SEEK_END). For more information about values, see the STREAM_SEEK enumeration. A pointer to the location where this method writes the value of the new seek pointer from the beginning of the stream. You can set this pointer to NULL. In this case, this method does not provide the new seek pointer. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The seek pointer was successfully adjusted.| |E_PENDING | Asynchronous Storage only: Part or all of the stream data is currently unavailable. | |STG_E_INVALIDPOINTER | Indicates that *plibNewPosition* points to invalid memory, because *plibNewPosition* is not read.| |STG_E_INVALIDFUNCTION | The *dwOrigin* parameter contains an invalid value, or the *dlibMove* parameter contains a bad offset value. For example, the result of the seek pointer is a negative offset value.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| IStream::Seek changes the seek pointer so that subsequent read and write operations can be performed at a different location in the stream object. It is an error to seek before the beginning of the stream. It is not, however, an error to seek past the end of the stream. Seeking past the end of the stream is useful for subsequent write operations, as the stream byte range will be extended to the new seek position immediately before the write is complete. You can also use this method to obtain the current value of the seek pointer by calling this method with the dwOrigin parameter set to STREAM_SEEK_CUR and the dlibMove parameter set to 0 so that the seek pointer is not changed. The current seek pointer is returned in the plibNewPosition parameter. Read more on docs.microsoft.com. Changes the size of the stream object. Specifies the new size, in bytes, of the stream. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The size of the stream object was successfully changed.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable.| |STG_E_MEDIUMFULL | The stream size is not changed because there is no space left on the storage device.| |STG_E_INVALIDFUNCTION | The value of the *libNewSize* parameter is not supported by the implementation. Not all streams support greater than 232 bytes. If a stream does not support more than 232 bytes, the high DWORD data type of *libNewSize* must be zero. If it is nonzero, the implementation may return STG_E_INVALIDFUNCTION. In general, COM-based implementations of the IStream interface do not support streams larger than 232 bytes.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| IStream::SetSize changes the size of the stream object. Call this method to preallocate space for the stream. If the libNewSize parameter is larger than the current stream size, the stream is extended to the indicated size by filling the intervening space with bytes of undefined value. This operation is similar to the ISequentialStream::Write method if the seek pointer is past the current end of the stream. If the libNewSize parameter is smaller than the current stream, the stream is truncated to the indicated size. The seek pointer is not affected by the change in stream size. Calling IStream::SetSize can be an effective way to obtain a large chunk of contiguous space. Read more on docs.microsoft.com. Copies a specified number of bytes from the current seek pointer in the stream to the current seek pointer in another stream. A pointer to the destination stream. The stream pointed to by pstm can be a new stream or a clone of the source stream. The number of bytes to copy from the source stream. A pointer to the location where this method writes the actual number of bytes read from the source. You can set this pointer to NULL. In this case, this method does not provide the actual number of bytes read. A pointer to the location where this method writes the actual number of bytes written to the destination. You can set this pointer to NULL. In this case, this method does not provide the actual number of bytes written. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The stream object was successfully copied.| |E_PENDING | Asynchronous Storage only: Part or all of the data to be copied is currently unavailable. | |STG_E_INVALIDPOINTER | The value of one of the pointer parameters is invalid.| |STG_E_MEDIUMFULL | The stream is not copied because there is no space left on the storage device.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| The CopyTo method copies the specified bytes from one stream to another. It can also be used to copy a stream to itself. The seek pointer in each stream instance is adjusted for the number of bytes read or written. This method is equivalent to reading cb bytes into memory using ISequentialStream::Read and then immediately writing them to the destination stream using ISequentialStream::Write, although IStream::CopyTo will be more efficient. The destination stream can be a clone of the source stream created by calling the IStream::Clone method. If IStream::CopyTo returns an error, you cannot assume that the seek pointers are valid for either the source or destination. Additionally, the values of pcbRead and pcbWritten are not meaningful even though they are returned. If IStream::CopyTo returns successfully, the actual number of bytes read and written are the same. To copy the remainder of the source from the current seek pointer, specify the maximum large integer value for the cb parameter. If the seek pointer is the beginning of the stream, this operation copies the entire stream. Read more on docs.microsoft.com. The Commit method ensures that any changes made to a stream object open in transacted mode are reflected in the parent storage. Controls how the changes for the stream object are committed. See the STGC enumeration for a definition of these values. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | Changes to the stream object were successfully committed to the parent level.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable. | |STG_E_MEDIUMFULL | The commit operation failed due to lack of space on the storage device.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| The Commit method ensures that changes to a stream object opened in transacted mode are reflected in the parent storage. Changes that have been made to the stream since it was opened or last committed are reflected to the parent storage object. If the parent is opened in transacted mode, the parent may revert at a later time, rolling back the changes to this stream object. The compound file implementation does not support the opening of streams in transacted mode, so this method has very little effect other than to flush memory buffers. For more information, see IStream - Compound File Implementation. If the stream is open in direct mode, this method ensures that any memory buffers have been flushed out to the underlying storage object. This is much like a flush in traditional file systems. The IStream::Commit method is useful on a direct mode stream when the implementation of the IStream interface is a wrapper for underlying file system APIs. In this case, IStream::Commit would be connected to the file system's flush call. Read more on docs.microsoft.com. The Revert method discards all changes that have been made to a transacted stream since the last IStream::Commit call. On streams open in direct mode and streams using the COM compound file implementation of IStream::Revert, this method has no effect. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The stream was successfully reverted to its previous version.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable. | The Revert method discards changes made to a transacted stream since the last commit operation. The LockRegion method restricts access to a specified range of bytes in the stream. Integer that specifies the byte offset for the beginning of the range. Integer that specifies the length of the range, in bytes, to be restricted. Specifies the restrictions being requested on accessing the range. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The specified range of bytes was locked.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable. | |STG_E_INVALIDFUNCTION | Locking is not supported at all or the specific type of lock requested is not supported.| |STG_E_LOCKVIOLATION | Requested lock is supported, but cannot be granted because of an existing lock.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| The byte range of the stream can be extended. Locking an extended range for the stream is useful as a method of communication between different instances of the stream without changing data that is actually part of the stream. Three types of locking can be supported: locking to exclude other writers, locking to exclude other readers or writers, and locking that allows only one requester to obtain a lock on the given range, which is usually an alias for one of the other two lock types. A given stream instance might support either of the first two types, or both. The lock type is specified by dwLockType, using a value from the LOCKTYPE enumeration. Any region locked with IStream::LockRegion must later be explicitly unlocked by calling IStream::UnlockRegion with exactly the same values for the libOffset, cb, and dwLockType parameters. The region must be unlocked before the stream is released. Two adjacent regions cannot be locked separately and then unlocked with a single unlock call.

Notes to Callers

Since the type of locking supported is optional and can vary in different implementations of IStream, you must provide code to deal with the STG_E_INVALIDFUNCTION error. The LockRegion method has no effect in the compound file implementation, because the implementation does not support range locking.

Notes to Implementers

Support for this method is optional for implementations of stream objects since it may not be supported by the underlying file system. The type of locking supported is also optional. The STG_E_INVALIDFUNCTION error is returned if the requested type of locking is not supported. Read more on docs.microsoft.com. The UnlockRegion method removes the access restriction on a range of bytes previously restricted with IStream::LockRegion. Specifies the byte offset for the beginning of the range. Specifies, in bytes, the length of the range to be restricted. Specifies the access restrictions previously placed on the range. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The byte range was unlocked.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable.| |STG_E_INVALIDFUNCTION | Locking is not supported at all or the specific type of lock requested is not supported.| |STG_E_LOCKVIOLATION | The requested unlock operation cannot be granted.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| IStream::UnlockRegion unlocks a region previously locked with the IStream::LockRegion method. Locked regions must later be explicitly unlocked by calling IStream::UnlockRegion with exactly the same values for the libOffset, cb, and dwLockType parameters. The region must be unlocked before the stream is released. Two adjacent regions cannot be locked separately and then unlocked with a single unlock call. Read more on docs.microsoft.com. The Stat method retrieves the STATSTG structure for this stream. Pointer to a STATSTG structure where this method places information about this stream object. Read more on docs.microsoft.com. Specifies that this method does not return some of the members in the STATSTG structure, thus saving a memory allocation operation. Values are taken from the STATFLAG enumeration. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The STATSTG structure was successfully returned at the specified location.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable. | |STG_E_ACCESSDENIED | The caller does not have enough permissions for accessing statistics for this storage object.| |STG_E_INSUFFICIENTMEMORY | The STATSTG structure was not returned due to a lack of memory.| |STG_E_INVALIDFLAG | The value for the *grfStateFlag* parameter is not valid.| |STG_E_INVALIDPOINTER | The *pStatStg* pointer is not valid.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| IStream::Stat retrieves a pointer to the STATSTG structure that contains information about this open stream. When this stream is within a structured storage and IStorage::EnumElements is called, it creates an enumerator object with the IEnumSTATSTG interface on it, which can be called to enumerate the storages and streams through the STATSTG structures associated with each of them. Read more on docs.microsoft.com. The Clone method creates a new stream object with its own seek pointer that references the same bytes as the original stream. When successful, pointer to the location of an IStream pointer to the new stream object. If an error occurs, this parameter is NULL. Read more on docs.microsoft.com. This method can return one of these values. | Return code | Description | |----------------|---------------| |S_OK | The stream was successfully cloned.| |E_PENDING | Asynchronous Storage only: Part or all of the stream's data is currently unavailable. | |STG_E_INSUFFICIENTMEMORY | The stream was not cloned due to a lack of memory.| |STG_E_INVALIDPOINTER | The ppStm pointer is not valid.| |STG_E_REVERTED | The object has been invalidated by a revert operation above it in the transaction tree.| The Clone method creates a new stream object for accessing the same bytes but using a separate seek pointer. The new stream object sees the same data as the source-stream object. Changes written to one object are immediately visible in the other. Range locking is shared between the stream objects. The initial setting of the seek pointer in the cloned stream instance is the same as the current setting of the seek pointer in the original stream at the time of the clone operation. Read more on docs.microsoft.com. The IID guid for this interface. {0000000c-0000-0000-c000-000000000046} Maps a name to a member of a type, or binds global variables and functions contained in a type library. The name to be bound. The hash value for the name computed by LHashValOfNameSys. One or more of the flags defined in the INVOKEKIND enumeration. Specifies whether the name was referenced as a method or a property. When binding to a variable, specify the flag INVOKE_PROPERTYGET. Specify zero to bind to any type of member. If a FUNCDESC or VARDESC was returned, then ppTInfo points to a pointer to the type description that contains the item to which it is bound. Indicates whether the name bound to is a VARDESC, FUNCDESC, or TYPECOMP. If there was no match, DESCKIND_NONE. The bound-to VARDESC, FUNCDESC, or ITypeComp interface. This method can return one of these values. This doc was truncated. Use Bind for binding to the variables and methods of a type, or for binding to the global variables and methods in a type library. The returned DESCKIND pointer pDescKind indicates whether the name was bound to a VARDESC, a FUNCDESC, or to an ITypeComp instance. The returned pBindPtr points to the VARDESC, FUNCDESC, or ITypeComp. If a data member or method is bound to, then ppTInfopoints to the type description that contains the method or data member. If Bind binds the name to a nested binding context, it returns a pointer to an ITypeComp instance in pBindPtr and a null type description pointer in ppTInfo. For example, if the name of a type description is passed for a module (TKIND_MODULE), enumeration (TKIND_ENUM), or coclass (TKIND_COCLASS), Bind returns the ITypeComp instance of the type description for the module, enumeration, or coclass. This feature supports languages such as Visual Basic that allow references to members of a type description to be qualified by the name of the type description. For example, a function in a module can be referenced by modulename.functionname. The members of TKIND_ENUM, TKIND_MODULE, and TKIND_COCLASS types marked as Application objects can be bound to directly from ITypeComp, without specifying the name of the module. The ITypeComp of a coclass defers to the ITypeComp of its default interface. As with other methods of ITypeComp, ITypeInfo, and ITypeInfo, the calling code is responsible for releasing the returned object instances or structures. If a VARDESC or FUNCDESC is returned, the caller is responsible for deleting it with the returned type description and releasing the type description instance itself. Otherwise, if an ITypeComp instance is returned, the caller must release it. Special rules apply if you call a type library's Bind method, passing it the name of a member of an Application object class (a class that has the TYPEFLAG_FAPPOBJECT flag set). In this case, Bind returns DESCKIND_IMPLICITAPPOBJ in pDescKind, a VARDESC that describes the Application object in pBindPtr, and the ITypeInfo of the Application object class in ppTInfo. To bind to the object, ITypeInfo::GetTypeComp must make a call to get the ITypeComp of the Application object class, and then reinvoke its Bind method with the name initially passed to the type library's ITypeComp. The caller should use the returned ITypeInfo pointer (ppTInfo) to get the address of the member.
Note  The wflags parameter is the same as the wflags parameter in IDispatch::Invoke.
 
 Read more on docs.microsoft.com. Binds to the type descriptions contained within a type library. The name to be bound. The hash value for the name computed by LHashValOfName. An ITypeInfo of the type to which the name was bound. Passes a valid pointer, such as the address of an ITypeComp variable. This method can return one of these values. This doc was truncated. Use the function BindType for binding a type name to the ITypeInfo that describes the type. This function is invoked on the ITypeComp that is returned by ITypeLib::GetTypeComp to bind to types defined within that library. It can also be used in the future for binding to nested types. The IID guid for this interface. {00020403-0000-0000-c000-000000000046} Retrieves a TYPEATTR structure that contains the attributes of the type description. The attributes of this type description. This method can return one of these values. This doc was truncated. To free the TYPEATTR structure, use ITypeInfo::ReleaseTypeAttr. Retrieves the ITypeComp interface for the type description, which enables a client compiler to bind to the type description's members. The ITypeComp of the containing type library. This method can return one of these values. This doc was truncated. A client compiler can use the ITypeComp interface to bind to members of the type. Retrieves the FUNCDESC structure that contains information about a specified function. The index of the function whose description is to be returned. The index should be in the range of 0 to 1 less than the number of functions in this type. A FUNCDESC structure that describes the specified function. This method can return one of these values. This doc was truncated. The function ITypeInfo::GetFuncDesc provides access to a FUNCDESC structure that describes the function with the specified index. The FUNCDESC structure should be freed with ITypeInfo::ReleaseFuncDesc. The number of functions in the type is one of the attributes contained in the TYPEATTR structure. Retrieves a VARDESC structure that describes the specified variable. The index of the variable whose description is to be returned. The index should be in the range of 0 to 1 less than the number of variables in this type. A VARDESC that describes the specified variable. This method can return one of these values. This doc was truncated. To free the VARDESC structure, use ReleaseVarDesc. Retrieves the variable with the specified member ID or the name of the property or method and the parameters that correspond to the specified function ID. The ID of the member whose name (or names) is to be returned. The caller-allocated array. On return, each of the elements contains the name (or names) associated with the member. The length of the passed-in rgBstrNames array. The number of names in the rgBstrNames array. This method can return one of these values. This doc was truncated. The caller must release the returned BSTR array. If the member ID identifies a property that is implemented with property functions, the property name is returned. For property get functions, the names of the function and its parameters are always returned. For property put and put reference functions, the right side of the assignment is unnamed. If cMaxNames is less than is required to return all of the names of the parameters of a function, then only the names of the first cMaxNames - 1 parameters are returned. The names of the parameters are returned in the array in the same order that they appear elsewhere in the interface (for example, the same order in the parameter array associated with the FUNCDESC enumeration). If the type description inherits from another type description, this function is recursive to the base type description, if necessary, to find the item with the requested member ID. Read more on docs.microsoft.com. If a type description describes a COM class, it retrieves the type description of the implemented interface types. The index of the implemented type whose handle is returned. The valid range is 0 to the cImplTypes field in the TYPEATTR structure. A handle for the implemented interface (if any). This handle can be passed to ITypeInfo::GetRefTypeInfo to get the type description. This method can return one of these values. This doc was truncated. If the TKIND_DISPATCH type description is for a dual interface, the TKIND_INTERFACE type description can be obtained by calling GetRefTypeOfImplType with an index of –1, and by passing the returned pRefTypehandle to GetRefTypeInfo to retrieve the type information. Retrieves the IMPLTYPEFLAGS enumeration for one implemented interface or base interface in a type description. The index of the implemented interface or base interface for which to get the flags. The IMPLTYPEFLAGS enumeration value. This method can return one of these values. This doc was truncated. The flags are associated with the act of inheritance, and not with the inherited interface. Maps between member names and member IDs, and parameter names and parameter IDs. An array of names to be mapped. The count of the names to be mapped. Caller-allocated array in which name mappings are placed. This method can return one of these values. This doc was truncated. The function GetIDsOfNames maps the name of a member (rgszNames[0]) and its parameters (rgszNames[1] ...rgszNames[cNames- 1]) to the ID of the member (pMemId[0]), and to the IDs of the specified parameters (pMemId[1] ... pMemId[cNames- 1]). The IDs of parameters are 0 for the first parameter in the member function's argument list, 1 for the second, and so on. If the type description inherits from another type description, this function is recursive to the base type description, if necessary, to find the item with the requested member ID. Read more on docs.microsoft.com. Invokes a method, or accesses a property of an object, that implements the interface described by the type description. An instance of the interface described by this type description. The interface member. Flags describing the context of the invoke call. This doc was truncated. Read more on docs.microsoft.com. An array of arguments, an array of DISPIDs for named arguments, and counts of the number of elements in each array. The result. Should be null if the caller does not expect any result. If wFlags specifies DISPATCH_PROPERTYPUT or DISPATCH_PROPERTYPUTREF, pVarResultis is ignored. An exception information structure, which is filled in only if DISP_E_EXCEPTION is returned. If pExcepInfo is null on input, only an HRESULT error will be returned. If Invoke returns DISP_E_TYPEMISMATCH, puArgErr indicates the index (within rgvarg) of the argument with incorrect type. If more than one argument returns an error, puArgErr indicates only the first argument with an error. Arguments in pDispParams->rgvarg appear in reverse order, so the first argument is the one having the highest index in the array. This parameter cannot be null. This doc was truncated. Use the function ITypeInfo::Invoke to access a member of an object or invoke a method that implements the interface described by this type description. For objects that support the IDispatch interface, you can use Invoke to implement IDispatch::Invoke. ITypeInfo::Invoke takes a pointer to an instance of the class. Otherwise, its parameters are the same as IDispatch::Invoke, except that ITypeInfo::Invoke omits the refiid and lcid parameters. When called, ITypeInfo::Invoke performs the actions described by the IDispatch::Invoke parameters on the specified instance. For VTBL interface members, ITypeInfo::Invoke passes the LCID of the type information into parameters tagged with the lcid attribute, and the returned value into the retval attribute. If the type description inherits from another type description, this function recurses on the base type description to find the item with the requested member ID. Read more on docs.microsoft.com. Retrieves the documentation string, the complete Help file name and path, and the context ID for the Help topic for a specified type description. The ID of the member whose documentation is to be returned. The name of the specified item. If the caller does not need the item name, pBstrName can be null. The documentation string for the specified item. If the caller does not need the documentation string, pBstrDocString can be null. The Help localization context. If the caller does not need the Help context, it can be null. The fully qualified name of the file containing the DLL used for Help file. If the caller does not need the file name, it can be null. This method can return one of these values. This doc was truncated. The function GetDocumentation provides access to the documentation for the member specified by the memid parameter. If the passed-in memid is MEMBERID_NIL, then the documentation for the type description is returned. If the type description inherits from another type description, this function is recursive to the base type description, if necessary, to find the item with the requested member ID. The caller should use SysFreeString to free the BSTRs referenced by pBstrName, pBstrDocString, and pBstrHelpFile. Read more on docs.microsoft.com. Retrieves a description or specification of an entry point for a function in a DLL. The ID of the member function whose DLL entry description is to be returned. The kind of member identified by memid. This is important for properties, because one memid can identify up to three separate functions. If not null, the function sets pBstrDllName to the name of the DLL. If not null, the function sets pBstrName to the name of the entry point. If the entry point is specified by an ordinal, this argument is null. If not null, and if the function is defined by an ordinal, the function sets pwOrdinal to the ordinal. This method can return one of these values. This doc was truncated. The caller passes in a member ID, which represents the member function whose entry description is desired. If the function has a DLL entry point, the name of the DLL that contains the function, as well as its name or ordinal identifier, are placed in the passed-in pointers allocated by the caller. If there is no DLL entry point for the function, an error is returned. If the type description inherits from another type description, this function is recursive to the base type description, if necessary, to find the item with the requested member ID. The caller should use SysFreeString to free the BSTRs referenced by pBstrName and pBstrDllName. Read more on docs.microsoft.com. If a type description references other type descriptions, it retrieves the referenced type descriptions. A handle to the referenced type description to return. The referenced type description. This method can return one of these values. This doc was truncated. On return, the second parameter contains a pointer to a pointer to a type description that is referenced by this type description. A type description must have a reference to each type description that occurs as the type of any of its variables, function parameters, or function return types. For example, if the type of a data member is a record type, the type description for that data member contains the hRefType of a referenced type description. To get a pointer to the type description, the reference is passed to GetRefTypeInfo. Retrieves the addresses of static functions or variables, such as those defined in a DLL. The member ID of the static member whose address is to be retrieved. The member ID is defined by the DISPID. Indicates whether the member is a property, and if so, what kind. The static member. This method can return one of these values. This doc was truncated. The addresses are valid until the caller releases its reference to the type description. The invKind parameter can be ignored unless the address of a property function is being requested. If the type description inherits from another type description, this function is recursive to the base type description, if necessary, to find the item with the requested member ID. Read more on docs.microsoft.com. Creates a new instance of a type that describes a component object class (coclass). The controlling IUnknown. If Null, then a stand-alone instance is created. If valid, then an aggregate object is created. An ID for the interface that the caller will use to communicate with the resulting object. An instance of the created object. This doc was truncated. For types that describe a component object class (coclass), CreateInstance creates a new instance of the class. Normally, CreateInstance calls CoCreateInstance with the type description's GUID. For an Application object, it first calls GetActiveObject. If the application is active, GetActiveObject returns the active object; otherwise, if GetActiveObject fails, CreateInstance calls CoCreateInstance. Retrieves marshaling information. The member ID that indicates which marshaling information is needed. The opcode string used in marshaling the fields of the structure described by the referenced type description, or null if there is no information to return. This method can return one of these values. This doc was truncated. If the passed-in member ID is MEMBERID_NIL, the function returns the opcode string for marshaling the fields of the structure described by the type description. Otherwise, it returns the opcode string for marshaling the function specified by the index. If the type description inherits from another type description, this function recurses on the base type description, if necessary, to find the item with the requested member ID. Read more on docs.microsoft.com. Retrieves the containing type library and the index of the type description within that type library. The containing type library. The index of the type description within the containing type library. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Releases a TYPEATTR previously returned by ITypeInfo::GetTypeAttr. The TYPEATTR to be freed. Learn more about this API from docs.microsoft.com. Releases a FUNCDESC previously returned by ITypeInfo::GetFuncDesc. The FUNCDESC to be freed. Learn more about this API from docs.microsoft.com. Releases a VARDESC previously returned by ITypeInfo::GetVarDesc. The VARDESC to be freed. Learn more about this API from docs.microsoft.com. The IID guid for this interface. {00020401-0000-0000-c000-000000000046} Provides the number of type descriptions that are in a type library. The number of type descriptions in the type library. Learn more about this API from docs.microsoft.com. Retrieves the specified type description in the library. The index of the interface to be returned. If successful, returns a pointer to the pointer to the ITypeInfo interface. This method can return one of these values. This doc was truncated. For dual interfaces, GetTypeInfo returns only the TKIND_DISPATCH type information. To get the TKIND_INTERFACE type information, GetRefTypeOfImplType can be called on the TKIND_DISPATCH type information, passing an index of –1. Then, the returned type information handle can be passed to GetRefTypeInfo. Retrieves the type of a type description. The index of the type description within the type library. The TYPEKIND enumeration value for the type description. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Retrieves the type description that corresponds to the specified GUID. The GUID of the type description. The ITypeInfo interface. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Retrieves the structure that contains the library's attributes. The library's attributes. This method can return one of these values. This doc was truncated. Use ITypeLib::ReleaseTLibAttr to free the memory occupied by the TLIBATTR structure. Enables a client compiler to bind to the types, variables, constants, and global functions for a library. The ITypeComp instance for this ITypeLib. A client compiler uses the methods in the ITypeComp interface to bind to types in ITypeLib, as well as to the global functions, variables, and constants defined in ITypeLib This method can return one of these values. This doc was truncated. The Bind function of the returned TypeComp binds to global functions, variables, constants, enumerated values, and coclass members. The Bind function also binds the names of the TYPEKIND enumerations of TKIND_MODULE, TKIND_ENUM, and TKIND_COCLASS. These names shadow any global names defined within the type information. The members of TKIND_ENUM, TKIND_MODULE, and TKIND_COCLASS types marked as Application objects can be directly bound to from ITypeComp without specifying the name of the module. ITypeComp::Bind and ITypeComp::BindType accept only unqualified names. ITypeLib::GetTypeComp returns a pointer to the ITypeComp interface, which is then used to bind to global elements in the library. The names of some types (TKIND_ENUM, TKIND_MODULE, and TKIND_COCLASS) share the name space with variables, functions, constants, and enumerators. If a member requires qualification to differentiate it from other items in the name space, GetTypeComp can be called successively for each qualifier in order to bind to the desired member. This allows programming language compilers to access members of modules, enumerations, and coclasses, even though the member can't be bound to with a qualified name. Read more on docs.microsoft.com. Retrieves the documentation string for the library, the complete Help file name and path, and the context identifier for the library Help topic in the Help file. The index of the type description whose documentation is to be returned. If index is -1, then the documentation for the library itself is returned. The name of the specified item. If the caller does not need the item name, then pBstrName can be null. The documentation string for the specified item. If the caller does not need the documentation string, then pBstrDocString can be null.. The Help context identifier (ID) associated with the specified item. If the caller does not need the Help context ID, then pdwHelpContext can be null. The fully qualified name of the Help file. If the caller does not need the Help file name, then pBstrHelpFile can be null. This method can return one of these values. This doc was truncated. The caller should free the parameters pBstrName, pBstrDocString, and pBstrHelpFile. Indicates whether a passed-in string contains the name of a type or member described in the library. The string to test. If this method is successful, szNameBuf is modified to match the case (capitalization) found in the type library. The hash value of szNameBuf. True if szNameBuf was found in the type library; otherwise false. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Finds occurrences of a type description in a type library. This may be used to quickly verify that a name exists in a type library. The name to search for. A hash value to speed up the search, computed by the LHashValOfNameSys function. If lHashVal = 0, a value is computed. An array of pointers to the type descriptions that contain the name specified in szNameBuf. This parameter cannot be null. An array of the found items; rgMemId[i] is the MEMBERID that indexes into the type description specified by ppTInfo[i]. This parameter cannot be null. On entry, indicates how many instances to look for. For example, *pcFound = 1 can be called to find the first occurrence. The search stops when one is found. On exit, indicates the number of instances that were found. If the in and out values of *pcFound are identical, there may be more type descriptions that contain the name. Read more on docs.microsoft.com. This method can return one of these values. This doc was truncated. Passing *pcFound = n indicates that there is enough room in the ppTInfo and rgMemId arrays for n (ptinfo, memid) pairs. The function returns MEMBERID_NIL in rgMemId[i], if the name in szNameBuf is the name of the type information in ppTInfo[i]. Releases the TLIBATTR originally obtained from GetLibAttr. The TLIBATTR to be freed. Learn more about this API from docs.microsoft.com. The IID guid for this interface. {00020402-0000-0000-c000-000000000046} Increments the reference count for an interface pointer to a COM object. You should call this method whenever you make a copy of an interface pointer. The method returns the new reference count. This value is intended to be used only for test purposes. A COM object uses a per-interface reference-counting mechanism to ensure that the object doesn't outlive references to it. You use **AddRef** to stabilize a copy of an interface pointer. It can also be called when the life of a cloned pointer must extend beyond the lifetime of the original pointer. The cloned pointer must be released by calling [IUnknown::Release](/windows/desktop/api/unknwn/nf-unknwn-iunknown-queryinterface(refiid_void)) on it. The internal reference counter that **AddRef** maintains should be a 32-bit unsigned integer. Read more on docs.microsoft.com. Decrements the reference count for an interface on a COM object. The method returns the new reference count. This value is intended to be used only for test purposes. When the reference count on an object reaches zero, **Release** must cause the interface pointer to free itself. When the released pointer is the only (formerly) outstanding reference to an object (whether the object supports single or multiple interfaces), the implementation must free the object. Note that aggregation of objects restricts the ability to recover interface pointers. Read more on docs.microsoft.com. The IID guid for this interface. {00000000-0000-0000-c000-000000000046} The LOCKTYPE enumeration values indicate the type of locking requested for the specified range of bytes. The values are used in the ILockBytes::LockRegion and IStream::LockRegion methods. Learn more about this API from docs.microsoft.com. If this lock is granted, the specified range of bytes can be opened and read any number of times, but writing to the locked range is prohibited except for the owner that was granted this lock. If this lock is granted, writing to the specified range of bytes is prohibited except by the owner that was granted this lock. If this lock is granted, no other LOCK_ONLYONCE lock can be obtained on the range. Usually this lock type is an alias for some other lock type. Thus, specific implementations can have additional behavior associated with this lock type. Represents a safe array. The array rgsabound is stored with the left-most dimension in rgsabound[0] and the right-most dimension in rgsabound[cDims - 1]. If an array was specified in a C-like syntax as a [2][5], it would have two elements in the rgsabound vector. Element 0 has an lLbound of 0 and a cElements of 2. Element 1 has an lLbound of 0 and a cElements of 5. The fFeatures flags describe attributes of an array that can affect how the array is released. The fFeatures field describes what type of data is stored in the SAFEARRAY and how the array is allocated. This allows freeing the array without referencing its containing variant. Read more on docs.microsoft.com. The number of dimensions. Flags. This doc was truncated. Read more on docs.microsoft.com. The size of an array element. The number of times the array has been locked without a corresponding unlock. The data. One bound for each dimension. Computes the amount of memory that must be allocated to store this struct, including the specified number of elements in the variable length inline array at the end. Represents the bounds of one dimension of the array. Learn more about this API from docs.microsoft.com. The number of elements in the dimension. The lower bound of the dimension. Contains statistical data about an open storage, stream, or byte-array object. Learn more about this API from docs.microsoft.com. A pointer to a NULL-terminated Unicode string that contains the name. Space for this string is allocated by the method called and freed by the caller (for more information, see CoTaskMemFree). To not return this member, specify the STATFLAG_NONAME value when you call a method that returns a STATSTG structure, except for calls to IEnumSTATSTG::Next, which provides no way to specify this value. Read more on docs.microsoft.com. Indicates the type of storage object. This is one of the values from the STGTY enumeration. Read more on docs.microsoft.com. Specifies the size, in bytes, of the stream or byte array. Indicates the last modification time for this storage, stream, or byte array. Indicates the creation time for this storage, stream, or byte array. Indicates the last access time for this storage, stream, or byte array. Indicates the access mode specified when the object was opened. This member is only valid in calls to Stat methods. Read more on docs.microsoft.com. Indicates the class identifier for the storage object; set to CLSID_NULL for new storage objects. This member is not used for streams or byte arrays. Indicates the current state bits of the storage object; that is, the value most recently set by the IStorage::SetStateBits method. This member is not valid for streams or byte arrays. Read more on docs.microsoft.com. Reserved for future use. Flags that indicate conditions for creating and deleting the object and access modes for the object. You can combine these flags, but you can only choose one flag from each group of related flags. Typically one flag from each of the access and sharing groups must be specified for all functions and methods which use these constants. Flags from other groups are optional. Identifies the target operating system platform. Learn more about this API from docs.microsoft.com. The target operating system for the type library is 16-bit Windows. By default, data members are packed. The target operating system for the type library is 32-bit Windows. By default, data members are naturally aligned (for example, 2-byte integers are aligned on even-byte boundaries; 4-byte integers are aligned on quad-word boundaries, and so on). The target operating system for the type library is Apple Macintosh. By default, all data members are aligned on even-byte boundaries. The target operating system for the type library is 64-bit Windows. Contains information about a type library. Information from this structure is used to identify the type library and to provide national language support for member names. Learn more about this API from docs.microsoft.com. The globally unique identifier. The locale identifier. The target hardware platform. The major version number. The minor version number. The library flags. Contains attributes of a type. Learn more about this API from docs.microsoft.com. The GUID of the type information. The locale of member names and documentation strings. Reserved. The constructor ID, or MEMBERID_NIL if none. The destructor ID, or MEMBERID_NIL if none. Reserved. The size of an instance of this type. The kind of type. The number of functions. The number of variables or data members. The number of implemented interfaces. The size of this type's VTBL. The byte alignment for an instance of this type. A value of 0 indicates alignment on the 64K boundary; 1 indicates no special alignment. For other values, n indicates aligned on byte n. The type flags. See TYPEFLAGS. The major version number. The minor version number. If typekind is TKIND_ALIAS, specifies the type for which this type is an alias. The IDL attributes of the described type. Describes the type of a variable, the return type of a function, or the type of a function parameter. If the variable is VT_SAFEARRAY or VT_PTR, the union portion of the TYPEDESC contains a pointer to a TYPEDESC that specifies the element type. The variant type. Specifies a type. Learn more about this API from docs.microsoft.com. A set of enumerators. A structure with no methods. A module that can only have static functions and data (for example, a DLL). A type that has virtual and pure functions. A set of methods and properties that are accessible through IDispatch::Invoke. By default, dual interfaces return TKIND_DISPATCH. A set of implemented component object interfaces. A type that is an alias for another type. A union, all of whose members have an offset of zero. End of enum marker. Describes a variable, constant, or data member. Learn more about this API from docs.microsoft.com. The member ID. Reserved. The variable type. The variable flags. See VARFLAGS. The variable type. Specifies variable flags. Learn more about this API from docs.microsoft.com. Assignment to the variable should not be allowed. The variable returns an object that is a source of events. The variable supports data binding. When set, any attempt to directly change the property results in a call to IPropertyNotifySink::OnRequestEdit. The implementation of OnRequestEdit determines if the change is accepted. The variable is displayed to the user as bindable. VARFLAG_FBINDABLE must also be set. The variable is the single property that best represents the object. Only one variable in type information can have this attribute. The variable should not be displayed to the user in a browser, although it exists and is bindable. The variable should not be accessible from macro languages. This flag is intended for system-level variables or variables that you do not want type browsers to display. Permits an optimization in which the compiler looks for a member named "xyz" on the type of abc. If such a member is found and is flagged as an accessor function for an element of the default collection, then a call is generated to that member function. Permitted on members in dispinterfaces and interfaces; not permitted on modules. The variable is the default display in the user interface. The variable appears in an object browser, but not in a properties browser. Tags the interface as having default behaviors. The variable is mapped as individual bindable properties. Specifies the variable type. Learn more about this API from docs.microsoft.com. The variable is a field or member of the type. It exists at a fixed offset within each instance of the type. There is only one instance of the variable. The VARDESC describes a symbolic constant. There is no memory associated with it. The variable can only be accessed through IDispatch::Invoke. Describes an array, its element type, and its dimension. Learn more about this API from docs.microsoft.com. The element type. The dimension count. A variable-length array containing one element for each dimension. Computes the amount of memory that must be allocated to store this struct, including the specified number of elements in the variable length inline array at the end. Initializes a new instance of a record. An instance of a record. This method can return one of these values. This doc was truncated. The caller must allocate the memory of the record by its appropriate size using the GetSize method. RecordInit sets all contents of the record to 0 and the record should hold no resources. Read more on docs.microsoft.com. Releases object references and other values of a record without deallocating the record. The record to be cleared. This method can return one of these values. This doc was truncated. RecordClear releases memory blocks held by VT_PTR or VT_SAFEARRAY instance fields. The caller needs to free the instance fields memory, RecordClear will do nothing if there are no resources held. Copies an existing record into the passed in buffer. The current record instance. The destination where the record will be copied. This method can return one of these values. This doc was truncated. RecordCopy will release the resources in the destination first. The caller is responsible for allocating sufficient memory in the destination by calling GetSize or RecordCreate. If RecordCopy fails to copy any of the fields then all fields will be cleared, as though RecordClear had been called. Gets the GUID of the record type. The class GUID of the TypeInfo that describes the UDT. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Gets the name of the record type. The name. This method can return one of these values. This doc was truncated. The caller must free the BSTR by calling SysFreeString. Gets the number of bytes of memory necessary to hold the record instance. The size of a record instance, in bytes. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Retrieves the type information that describes a UDT or safearray of UDTs. The information type of the record. This method can return one of these values. This doc was truncated. AddRef is called on the pointer ppTypeInfo. Returns a pointer to the VARIANT containing the value of a given field name. The instance of a record. The field name. The VARIANT that you want to hold the value of the field name, szFieldName. On return, places a copy of the field's value in the variant. This method can return one of these values. This doc was truncated. The VARIANT that you pass in contains a copy of the field's value upon return. If you modify the VARIANT then the underlying record field does not change. The caller allocates memory of the VARIANT. The method VariantClear is called for pvarField before copying. Read more on docs.microsoft.com. Returns a pointer to the value of a given field name without copying the value and allocating resources. The instance of a record. The name of the field. The VARIANT that will contain the UDT upon return. Receives the value of the field upon return. This method can return one of these values. This doc was truncated. Upon return, the VARIANT you pass contains a direct pointer to the record's field, ppvDataCArray. If you modify the VARIANT, then the underlying record field will change. The caller allocates memory of the VARIANT, but does not own the memory so cannot free pvarField. This method calls VariantClear for pvarField before filling in the requested field. Read more on docs.microsoft.com. Puts a variant into a field. The only legal values for the wFlags parameter is INVOKE_PROPERTYPUT or INVOKE_PROPERTYPUTREF. If INVOKE_PROPERTYPUTREF is passed in then PutField just assigns the value of the variant that is passed in to the field using normal coercion rules. If INVOKE_PROPERTYPUT is passed in then specific rules apply. If the field is declared as a class that derives from IDispatch and the field's value is NULL then an error will be returned. If the field's value is not NULL then the variant will be passed to the default property supported by the object referenced by the field. If the field is not declared as a class derived from IDispatch then an error will be returned. If the field is declared as a variant of type VT_Dispatch then the default value of the object is assigned to the field. Otherwise, the variant's value is assigned to the field. Read more on docs.microsoft.com. The pointer to an instance of the record. The name of the field of the record. The pointer to the variant. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Passes ownership of the data to the assigned field by placing the actual data into the field. The only legal values for the wFlags parameter is INVOKE_PROPERTYPUT or INVOKE_PROPERTYPUTREF. An instance of the record described by IRecordInfo. The name of the field of the record. The variant to be put into the field. This method can return one of these values. This doc was truncated. Learn more about this API from docs.microsoft.com. Gets the names of the fields of the record. The number of names to return. The name of the array of type BSTR. If the rgBstrNames parameter is NULL, then pcNames is returned with the number of field names. It the rgBstrNames parameter is not NULL, then the string names contained in rgBstrNames are returned. If the number of names in pcNames and rgBstrNames are not equal then the lesser number of the two is the number of returned field names. The caller needs to free the BSTRs inside the array returned in rgBstrNames. Read more on docs.microsoft.com. This method can return one of these values. This doc was truncated. The caller should allocate memory for the array of BSTRs. If the array is larger than needed, set the unused portion to 0. On return, the caller will need to free each contained BSTR using SysFreeString. In case of out of memory, pcNames points to error code. Read more on docs.microsoft.com. Determines whether the record that is passed in matches that of the current record information. The information of the record. This doc was truncated. Learn more about this API from docs.microsoft.com. Allocates memory for a new record, initializes the instance and returns a pointer to the record. This method returns a pointer to the created record. The memory is set to zeros before it is returned. The records created must be freed by calling RecordDestroy. Read more on docs.microsoft.com. Creates a copy of an instance of a record to the specified location. An instance of the record to be copied. The new record with data copied from pvSource. This method can return one of these values. This doc was truncated. The records created must be freed by calling RecordDestroy. Releases the resources and deallocates the memory of the record. An instance of the record to be destroyed. This method can return one of these values. This doc was truncated. RecordClear is called to release the resources held by the instance of a record without deallocating memory.
Note  This method can only be called on records allocated through RecordCreate and RecordCreateCopy. If you allocate the record yourself, you cannot call this method.
 
 Read more on docs.microsoft.com. The IID guid for this interface. {0000002f-0000-0000-c000-000000000046} Contains information needed for transferring a structure element, parameter, or function return value between processes. Learn more about this API from docs.microsoft.com. The default value for the parameter, if PARAMFLAG_FHASDEFAULT is specified in wParamFlags. The parameter flags. See PARAMFLAG Constants. Contains information about the default value of a parameter. Learn more about this API from docs.microsoft.com. The size of the structure. The default value of the parameter. Specifies the variant types. The following table shows where these values can be used. This doc was truncated. Read more on docs.microsoft.com. Not specified. Null. A 2-byte integer. A 4-byte integer. A 4-byte real. An 8-byte real. Currency. A date. A string. An IDispatch pointer. An SCODE value. A Boolean value. True is -1 and false is 0. A variant pointer. An IUnknown pointer. A 16-byte fixed-pointer value. A character. An unsigned character. An unsigned short. An unsigned long. A 64-bit integer. A 64-bit unsigned integer. An integer. An unsigned integer. A C-style void. An HRESULT value. A pointer type. A safe array. Use VT_ARRAY in VARIANT. A C-style array. A user-defined type. A null-terminated string. A wide null-terminated string. A user-defined type. A signed machine register size width. An unsigned machine register size width. A FILETIME value. Length-prefixed bytes. The name of the stream follows. The name of the storage follows. The stream contains an object. The storage contains an object. The blob contains an object. A clipboard format. A class ID. A stream with a GUID version. Reserved. A simple counted array. A SAFEARRAY pointer. A void pointer for local use. VARIANTARG describes arguments passed within DISPPARAMS, and VARIANT to specify variant data that cannot be passed by reference. Learn more about this API from docs.microsoft.com. Contains information about a system appbar message. Learn more about this API from docs.microsoft.com. Type: DWORD The size of the structure, in bytes. Read more on docs.microsoft.com. Type: HWND The handle to the appbar window. Not all messages use this member. See the individual message page to see if you need to provide an hWind value. Read more on docs.microsoft.com. Type: UINT An application-defined message identifier. The application uses the specified identifier for notification messages that it sends to the appbar identified by the hWnd member. This member is used when sending the ABM_NEW message. Read more on docs.microsoft.com. Type: UINT A value that specifies an edge of the screen. This member is used when sending one of these messages: This doc was truncated. Read more on docs.microsoft.com. Type: RECT A RECT structure whose use varies depending on the message: This doc was truncated. Read more on docs.microsoft.com. Type: LPARAM A message-dependent value. This member is used with these messages: This doc was truncated. Read more on docs.microsoft.com. Defines the initialization parameters passed to the window procedure of an application. These members are identical to the parameters of the CreateWindowEx function. (Unicode) Because the lpszClass member can contain a pointer to a local (and thus inaccessible) atom, do not obtain the class name by using this member. Use the GetClassName function instead. You should access the data represented by the lpCreateParams member using a pointer that has been declared using the UNALIGNED type, because the pointer may not be DWORD aligned. This is demonstrated in the following example: This doc was truncated. Read more on docs.microsoft.com. Type: LPVOID Contains additional data which may be used to create the window. If the window is being created as a result of a call to the CreateWindow or CreateWindowEx function, this member contains the value of the lpParam parameter specified in the function call. If the window being created is a MDI client window, this member contains a pointer to a CLIENTCREATESTRUCT structure. If the window being created is a MDI child window, this member contains a pointer to an MDICREATESTRUCT structure. If the window is being created from a dialog template, this member is the address of a SHORT value that specifies the size, in bytes, of the window creation data. The value is immediately followed by the creation data. For more information, see the following Remarks section. Read more on docs.microsoft.com. Type: HINSTANCE A handle to the module that owns the new window. Read more on docs.microsoft.com. Type: HMENU A handle to the menu to be used by the new window. Read more on docs.microsoft.com. Type: HWND A handle to the parent window, if the window is a child window. If the window is owned, this member identifies the owner window. If the window is not a child or owned window, this member is NULL. Read more on docs.microsoft.com. Type: int The height of the new window, in pixels. Read more on docs.microsoft.com. Type: int The width of the new window, in pixels. Read more on docs.microsoft.com. Type: int The y-coordinate of the upper left corner of the new window. If the new window is a child window, coordinates are relative to the parent window. Otherwise, the coordinates are relative to the screen origin. Read more on docs.microsoft.com. Type: int The x-coordinate of the upper left corner of the new window. If the new window is a child window, coordinates are relative to the parent window. Otherwise, the coordinates are relative to the screen origin. Read more on docs.microsoft.com. Type: LPCTSTR The name of the new window. Read more on docs.microsoft.com. Type: LPCTSTR A pointer to a null-terminated string or an atom that specifies the class name of the new window. Read more on docs.microsoft.com. Type: DWORD The extended window style for the new window. For a list of possible values, see Extended Window Styles. Read more on docs.microsoft.com. Contains window class information. (Unicode) > [!NOTE] > The winuser.h header defines WNDCLASSEX as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com. Type: UINT The size, in bytes, of this structure. Set this member to sizeof(WNDCLASSEX). Be sure to set this member before calling the GetClassInfoEx function. Read more on docs.microsoft.com. Type: UINT The class style(s). This member can be any combination of the Class Styles. Read more on docs.microsoft.com. Type: WNDPROC A pointer to the window procedure. You must use the CallWindowProc function to call the window procedure. For more information, see WindowProc. Read more on docs.microsoft.com. Type: int The number of extra bytes to allocate following the window-class structure. The system initializes the bytes to zero. Read more on docs.microsoft.com. Type: int The number of extra bytes to allocate following the window instance. The system initializes the bytes to zero. If an application uses WNDCLASSEX to register a dialog box created by using the CLASS directive in the resource file, it must set this member to DLGWINDOWEXTRA. Read more on docs.microsoft.com. Type: HINSTANCE A handle to the instance that contains the window procedure for the class. Read more on docs.microsoft.com. Type: HICON A handle to the class icon. This member must be a handle to an icon resource. If this member is NULL, the system provides a default icon. Read more on docs.microsoft.com. Type: HCURSOR A handle to the class cursor. This member must be a handle to a cursor resource. If this member is NULL, an application must explicitly set the cursor shape whenever the mouse moves into the application's window. Read more on docs.microsoft.com. Type: HBRUSH A handle to the class background brush. This member can be a handle to the brush to be used for painting the background, or it can be a color value. A color value must be one of the following standard system colors (the value 1 must be added to the chosen color). If a color value is given, you must convert it to one of the following HBRUSH types: This doc was truncated. Read more on docs.microsoft.com. Type: LPCTSTR Pointer to a null-terminated character string that specifies the resource name of the class menu, as the name appears in the resource file. If you use an integer to identify the menu, use the MAKEINTRESOURCE macro. If this member is NULL, windows belonging to this class have no default menu. Read more on docs.microsoft.com. Type: LPCTSTR A pointer to a null-terminated string or is an atom. If this parameter is an atom, it must be a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpszClassName; the high-order word must be zero. If lpszClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names. The maximum length for lpszClassName is 256. If lpszClassName is greater than the maximum length, the RegisterClassEx function will fail. Read more on docs.microsoft.com. Type: HICON A handle to a small icon that is associated with the window class. If this member is NULL, the system searches the icon resource specified by the hIcon member for an icon of the appropriate size to use as the small icon. Read more on docs.microsoft.com. Identifies the dots per inch (dpi) setting for a monitor. All of these settings are affected by the PROCESS_DPI_AWARENESS of your application The effective DPI. This value should be used when determining the correct scale factor for scaling UI elements. This incorporates the scale factor set by the user for this specific display. The angular DPI. This DPI ensures rendering at a compliant angular resolution on the screen. This does not include the scale factor set by the user for this specific display. The raw DPI. This value is the linear DPI of the screen as measured on the screen itself. Use this value when you want to read the pixel density and not the recommended scaling setting. This does not include the scale factor set by the user for this specific display and is not guaranteed to be a supported DPI value. The default DPI setting for a monitor is MDT_EFFECTIVE_DPI. Gets the length of the BSTR in characters. The DECIMAL structure represents a decimal data type that provides a sign and scale for a number. Reserved. The high 32 bits of the number. The **HRESULT** data type is the same as the [SCODE](scode.md) data type. An **HRESULT** value consists of the following fields: - A 1-bit code indicating severity, where zero represents success and 1 represents failure. - A 4-bit reserved value. - An 11-bit code indicating responsibility for the error or warning, also known as a facility code. - A 16-bit code describing the error or warning. Most MAPI interface methods and functions return **HRESULT** values to provide detailed cause formation. **HRESULT** values are also used widely in OLE interface methods. OLE provides several macros for converting between **HRESULT** values and **SCODE** values, another common data type for error handling. > [!NOTE] > In 64-bit MAPI, **HRESULT** is still a 32-bit value. For information about the OLE use of **HRESULT** values, see the *OLE Programmer's Reference*. For more information about the use of these values in MAPI, see [Error Handling](error-handling-in-mapi.md) and any of the following interface methods: [IABLogon::GetLastError](iablogon-getlasterror.md) [IMAPISupport::GetLastError](imapisupport-getlasterror.md) [IMAPIControl::GetLastError](imapicontrol-getlasterror.md) [IMAPITable::GetLastError](imapitable-getlasterror.md) [IMAPIProp::GetLastError](imapiprop-getlasterror.md) [IMAPIViewAdviseSink::OnPrint](imapiviewadvisesink-onprint.md) Read more on docs.microsoft.com. A pointer to the IErrorInfo interface that provides more information about the error. You can specify to use the current IErrorInfo interface, or new IntPtr(-1) to ignore the current IErrorInfo interface and construct the exception just from the error code. , if it does not reflect an error. A pointer to a null-terminated, constant, ANSI character string. A pointer to the first character in the string. The content should be considered readonly, as it was typed as constant in the SDK. Gets the number of characters up to the first null character (exclusive). Returns a with a copy of this character array, decoding as UTF-8. A , or if is . Returns a span of the characters in this string, up to the first null character (exclusive). A pointer to a null-terminated, constant character string. A pointer to the first character in the string. The content should be considered readonly, as it was typed as constant in the SDK. Gets the number of characters up to the first null character (exclusive). Returns a with a copy of this character array, up to the first null character (exclusive). A , or if is . Returns a span of the characters in this string, up to the first null character (exclusive). Returns a span of the characters in this string, up to the first null character (exclusive). Returns a span of the characters in this string, up to the first null character (exclusive). The RECT structure defines a rectangle by the coordinates of its upper-left and lower-right corners. The RECT structure is identical to the RECTL structure. Specifies the x-coordinate of the upper-left corner of the rectangle. Specifies the y-coordinate of the upper-left corner of the rectangle. Specifies the x-coordinate of the lower-right corner of the rectangle. Specifies the y-coordinate of the lower-right corner of the rectangle. Represents a Win32 handle that can be closed with . The MONITORINFO structure contains information about a display monitor.The GetMonitorInfo function stores information in a MONITORINFO structure or a MONITORINFOEX structure.The MONITORINFO structure is a subset of the MONITORINFOEX structure. Learn more about this API from docs.microsoft.com. The size of the structure, in bytes. Set this member to sizeof ( MONITORINFO ) before calling the GetMonitorInfo function. Doing so lets the function determine the type of structure you are passing to it. Read more on docs.microsoft.com. A RECT structure that specifies the display monitor rectangle, expressed in virtual-screen coordinates. Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values. A RECT structure that specifies the work area rectangle of the display monitor, expressed in virtual-screen coordinates. Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values. A set of flags that represent attributes of the display monitor. The following flag is defined. This doc was truncated. Read more on docs.microsoft.com. Represents a Win32 handle that can be closed with . The IID guid for this interface. The reference that is returned comes from a permanent memory address, and is therefore safe to convert to a pointer and pass around or hold long-term. Retrieves a double value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_DOUBLE. Receives a double value. If the key is found and the data type is double, the method copies the value into this parameter. Otherwise, the original value of this parameter is not changed. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Creates the object associated with this activation object. Interface identifier (IID) of the requested interface. If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code. Some Microsoft Media Foundation objects must be shut down before being released. If so, the caller is responsible for shutting down the object that is returned in ppv. To shut down the object, do one of the following: This doc was truncated. Read more on docs.microsoft.com. Shuts down the created object. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. If you create an object by calling IMFActivate::ActivateObject, call ShutdownObject when you are done using the object. The component that calls ActivateObject—not the component that creates the activation object—is responsible for calling ShutdownObject. For example, in a typical playback application, the application creates activation objects for the media sinks, but the Media Session calls ActivateObject. Therefore the Media Session, not the application, calls ShutdownObject. After ShutdownObject is called, the activation object releases all of its internal references to the created object. If you call ActivateObject again, the activation object will create a new instance of the other object. Read more on docs.microsoft.com. Detaches the created object from the activation object. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. The activation object releases all of its internal references to the created object. If you call ActivateObject again, the activation object will create a new instance of the other object. The DetachObject method does not shut down the created object. If the DetachObject method succeeds, the client must shut down the created object. This rule applies only to objects that have a shutdown method or that support the IMFShutdown interface. See the remarks for IMFActivate::ActivateObject. Implementation of this method is optional. If the activation object does not support this method, the method returns E_NOTIMPL. Read more on docs.microsoft.com. The IID guid for this interface. {7fee9e9a-4a89-47a6-899c-b6a53a70fb67} Retrieves the value associated with a key. A GUID that identifies which value to retrieve. A pointer to a PROPVARIANT that receives the value. The method fills the PROPVARIANT with a copy of the stored value, if the value is found. Call PropVariantClear to free the memory allocated by this method. This parameter can be NULL. If this parameter is NULL, the method searches for the key and returns S_OK if the key is found, but does not copy the value. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves the data type of the value associated with a key. GUID that identifies which value to query. Receives a member of the MF_ATTRIBUTE_TYPE enumeration. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Queries whether a stored attribute value equals to a specified PROPVARIANT. GUID that identifies which value to query. PROPVARIANT that contains the value to compare. Receives a Boolean value indicating whether the attribute matches the value given in Value. See Remarks. This parameter must not be NULL. If this parameter is NULL, an access violation occurs. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. The method sets pbResult to FALSE for any of the following reasons: This doc was truncated. Read more on docs.microsoft.com. Compares the attributes on this object with the attributes on another object. Pointer to the IMFAttributes interface of the object to compare with this object. Member of the MF_ATTRIBUTES_MATCH_TYPE enumeration, specifying the type of comparison to make. Receives a Boolean value. The value is TRUE if the two sets of attributes match in the way specified by the MatchType parameter. Otherwise, the value is FALSE. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. If pThis is the object whose Compare method is called, and pTheirs is the object passed in as the pTheirs parameter, the following comparisons are defined by MatchType. This doc was truncated. Read more on docs.microsoft.com. Retrieves a UINT32 value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_UINT32. Receives a UINT32 value. If the key is found and the data type is UINT32, the method copies the value into this parameter. Otherwise, the original value of this parameter is not changed. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a UINT64 value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_UINT64. Receives a UINT64 value. If the key is found and the data type is UINT64, the method copies the value into this parameter. Otherwise, the original value of this parameter is not changed. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a double value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_DOUBLE. Receives a double value. If the key is found and the data type is double, the method copies the value into this parameter. Otherwise, the original value of this parameter is not changed. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a GUID value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_GUID. Receives a GUID value. If the key is found and the data type is GUID, the method copies the value into this parameter. Otherwise, the original value of this parameter is not changed. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves the length of a string value associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_STRING. If the key is found and the value is a string type, this parameter receives the number of characters in the string, not including the terminating NULL character. To get the string value, call IMFAttributes::GetString. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a wide-character string associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_STRING. Pointer to a wide-character array allocated by the caller. The array must be large enough to hold the string, including the terminating NULL character. If the key is found and the value is a string type, the method copies the string into this buffer. To find the length of the string, call IMFAttributes::GetStringLength. The size of the pwszValue array, in characters. This value includes the terminating NULL character. Receives the number of characters in the string, excluding the terminating NULL character. This parameter can be NULL. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. You can also use the IMFAttributes::GetAllocatedString method, which allocates the buffer to hold the string. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Gets a wide-character string associated with a key. This method allocates the memory for the string. A GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_STRING. If the key is found and the value is a string type, this parameter receives a copy of the string. The caller must free the memory for the string by calling CoTaskMemFree. Receives the number of characters in the string, excluding the terminating NULL character. This parameter must not be NULL. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To copy a string value into a caller-allocated buffer, use the IMFAttributes::GetString method. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves the length of a byte array associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_BLOB. If the key is found and the value is a byte array, this parameter receives the size of the array, in bytes. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To get the byte array, call IMFAttributes::GetBlob. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a byte array associated with a key. This method copies the array into a caller-allocated buffer. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_BLOB. Pointer to a buffer allocated by the caller. If the key is found and the value is a byte array, the method copies the array into this buffer. To find the required size of the buffer, call IMFAttributes::GetBlobSize. The size of the pBuf buffer, in bytes. Receives the size of the byte array. This parameter can be NULL. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. You can also use the IMFAttributes::GetAllocatedBlob method, which allocates the buffer to hold the byte array. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves a byte array associated with a key. This method allocates the memory for the array. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_BLOB. If the key is found and the value is a byte array, this parameter receives a copy of the array. The caller must free the memory for the array by calling CoTaskMemFree. Receives the size of the array, in bytes. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To copy a byte array value into a caller-allocated buffer, use the IMFAttributes::GetBlob method. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves an interface pointer associated with a key. GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_IUNKNOWN. Interface identifier (IID) of the interface to retrieve. Receives a pointer to the requested interface. The caller must release the interface. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Adds an attribute value with a specified key. A GUID that identifies the value to set. If this key already exists, the method overwrites the old value. A PROPVARIANT that contains the attribute value. The method copies the value. The PROPVARIANT type must be one of the types listed in the MF_ATTRIBUTE_TYPE enumeration. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This method checks whether the PROPVARIANT type is one of the attribute types defined in MF_ATTRIBUTE_TYPE, and fails if an unsupported type is used. However, this method does not check whether the PROPVARIANT is the correct type for the specified attribute GUID. (There is no programmatic way to associate attribute GUIDs with property types.) For a list of Media Foundation attributes and their data types, see Media Foundation Attributes. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Removes a key/value pair from the object's attribute list. GUID that identifies the value to delete. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. If the specified key does not exist, the method returns S_OK. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Removes all key/value pairs from the object's attribute list. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a UINT32 value with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. New value for this key. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the UINT32 value, call IMFAttributes::GetUINT32. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a UINT64 value with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. New value for this key. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the UINT64 value, call IMFAttributes::GetUINT64. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a double value with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. New value for this key. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the double value, call IMFAttributes::GetDouble. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a GUID value with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. New value for this key. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the GUID value, call IMFAttributes::GetGUID. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a wide-character string with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. Null-terminated wide-character string to associate with this key. The method stores a copy of the string. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the string, call IMFAttributes::GetString or IMFAttributes::GetAllocatedString. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates a byte array with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. Pointer to a byte array to associate with this key. The method stores a copy of the array. Size of the array, in bytes. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the byte array, call IMFAttributes::GetBlob or IMFAttributes::GetAllocatedBlob. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Associates an IUnknown pointer with a key. GUID that identifies the value to set. If this key already exists, the method overwrites the old value. IUnknown pointer to be associated with this key. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To retrieve the IUnknown pointer, call IMFAttributes::GetUnknown. It is not an error to call SetUnknown with pUnknown equal to NULL. However, GetUnknown will return MF_E_INVALIDTYPE. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Locks the attribute store so that no other thread can access it. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This method can cause a deadlock if a thread that calls LockStore waits on a thread that calls any other IMFAttributes methods on the same object. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Unlocks the attribute store after a call to the IMFAttributes::LockStore method. While the object is unlocked, multiple threads can access the object's attributes. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves the number of attributes that are set on this object. Receives the number of attributes. This parameter must not be NULL. If this parameter is NULL, an access violation occurs. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To enumerate all of the attributes, call IMFAttributes::GetItemByIndex for each index value. This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed: This doc was truncated. Read more on docs.microsoft.com. Retrieves an attribute at the specified index. Index of the attribute to retrieve. To get the number of attributes, call IMFAttributes::GetCount. Receives the GUID that identifies this attribute. Pointer to a PROPVARIANT that receives the value. This parameter can be NULL. If it is not NULL, the method fills the PROPVARIANT with a copy of the attribute value. Call PropVariantClear to free the memory allocated by this method. The method returns an HRESULT. Possible values include, but are not limited to, those in the following table. This doc was truncated. To enumerate all of an object's attributes in a thread-safe way, do the following: This doc was truncated. Read more on docs.microsoft.com. The IID guid for this interface. {2cd2d921-c447-44a7-a13c-4adabfc247e3} Contains media type information for registering a Media Foundation transform (MFT). Learn more about this API from docs.microsoft.com. The major media type. For a list of possible values, see Major Media Types. The media subtype. For a list of possible values, see the following topics: This doc was truncated. Read more on docs.microsoft.com. Specifies how to compare the attributes on two objects. Learn more about this API from docs.microsoft.com. Check whether all the attributes in pThis exist in pTheirs and have the same data, where pThis is the object whose Compare method is being called and pTheirs is the object given in the pTheirs parameter. Check whether all the attributes in pTheirs exist in pThis and have the same data, where pThis is the object whose Compare method is being called and pTheirs is the object given in the pTheirs parameter. Check whether both objects have identical attributes with the same data. Check whether the attributes that exist in both objects have the same data. Find the object with the fewest number of attributes, and check if those attributes exist in the other object and have the same data. Defines the data type for a key/value pair. Learn more about this API from docs.microsoft.com. Unsigned 32-bit integer. Unsigned 64-bit integer. Floating-point number. GUID value. NULL-terminated wide-character string. Byte array. IUnknown pointer. Non generic interface that allows constraining against a COM wrapper type directly. COM structs should implement . Contains extern methods from "api-ms-win-shcore-scaling-l1-1-1.dll". Contains extern methods from "GDI32.dll". Contains extern methods from "KERNEL32.dll". Contains extern methods from "MFPlat.dll". Contains extern methods from "OLEAUT32.dll". Contains extern methods from "SHELL32.dll". Contains extern methods from "USER32.dll". Queries the dots per inch (dpi) of a display. Handle of the monitor being queried. The type of DPI being queried. Possible values are from the MONITOR_DPI_TYPE enumeration. The value of the DPI along the X axis. This value always refers to the horizontal edge, even when the screen is rotated. The value of the DPI along the Y axis. This value always refers to the vertical edge, even when the screen is rotated. This function returns one of the following values. This doc was truncated. This API is not DPI aware and should not be used if the calling thread is per-monitor DPI aware. For the DPI-aware version of this API, see GetDpiForWindow. When you call GetDpiForMonitor, you will receive different DPI values depending on the DPI awareness of the calling application. DPI awareness is an application-level property usually defined in the application manifest. For more information about DPI awareness values, see PROCESS_DPI_AWARENESS. The following table indicates how the results will differ based on the PROCESS_DPI_AWARENESS value of your application. This doc was truncated. Read more on docs.microsoft.com. Sent prior to the WM\_CREATE message when a window is first created. Type: **LRESULT** If an application processes this message, it should return **TRUE** to continue creation of the window. If the application returns **FALSE**, the [**CreateWindow**](/windows/win32/api/winuser/nf-winuser-createwindowa) or [**CreateWindowEx**](/windows/win32/api/winuser/nf-winuser-createwindowexa) function will return a **NULL** handle. Learn more about this API from docs.microsoft.com. Notifies a window that its nonclient area is being destroyed. The DestroyWindow function sends the WM\_NCDESTROY message to the window following the WM\_DESTROY message. Type: **LRESULT** If an application processes this message, it should return zero. This message frees any memory internally allocated for the window. Sent when the contents of the clipboard have changed. If an application processes this message, it should return zero. To register a window to receive this message, use the [**AddClipboardFormatListener**](/windows/desktop/api/Winuser/nf-winuser-addclipboardformatlistener) function. Sent when a window is being destroyed. It is sent to the window procedure of the window being destroyed after the window is removed from the screen. Type: **LRESULT** If an application processes this message, it should return zero. If the window being destroyed is part of the clipboard viewer chain (set by calling the [**SetClipboardViewer**](/windows/win32/api/winuser/nf-winuser-setclipboardviewer) function), the window must remove itself from the chain by processing the [**ChangeClipboardChain**](/windows/win32/api/winuser/nf-winuser-changeclipboardchain) function before returning from the **WM\_DESTROY** message. Sent as a signal that a window or an application should terminate. Type: **LRESULT** If an application processes this message, it should return zero. An application can prompt the user for confirmation, prior to destroying a window, by processing the **WM\_CLOSE** message and calling the [**DestroyWindow**](/windows/win32/api/winuser/nf-winuser-destroywindow) function only if the user confirms the choice. By default, the [**DefWindowProc**](/windows/desktop/api/winuser/nf-winuser-defwindowproca) function calls the [**DestroyWindow**](/windows/win32/api/winuser/nf-winuser-destroywindow) function to destroy the window. Read more on docs.microsoft.com. Retrieves the bounding rectangle of the Windows taskbar. Returns **TRUE** if successful; otherwise, **FALSE**. Note that this applies only to the system taskbar. Other objects, particularly toolbars supplied with third-party software, also can be present. As a result, some of the screen area not covered by the Windows taskbar might not be visible to the user. To retrieve the area of the screen not covered by both the taskbar and other app bars the working area available to your application , use the [**GetMonitorInfo**](/windows/desktop/api/winuser/nf-winuser-getmonitorinfoa) function. The DeleteObject function deletes a logical pen, brush, font, bitmap, region, or palette, freeing all system resources associated with the object. After the object is deleted, the specified handle is no longer valid. A handle to a logical pen, brush, font, bitmap, region, or palette. If the function succeeds, the return value is nonzero. If the specified handle is not valid or is currently selected into a DC, the return value is zero. Do not delete a drawing object (pen or brush) while it is still selected into a DC. When a pattern brush is deleted, the bitmap associated with the brush is not deleted. The bitmap must be deleted independently. Read more on docs.microsoft.com. The GetDeviceCaps function retrieves device-specific information for the specified device. A handle to the DC. The return value specifies the value of the desired item. When nIndex is BITSPIXEL and the device has 15bpp or 16bpp, the return value is 16. When nIndex is SHADEBLENDCAPS: This doc was truncated. Read more on docs.microsoft.com. Closes an open object handle. A valid handle to an open object. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. If the application is running under a debugger, the function will throw an exception if it receives either a handle value that is not valid or a pseudo-handle value. This can happen if you close a handle twice, or if you call CloseHandle on a handle returned by the FindFirstFile function instead of calling the FindClose function. The CloseHandle function closes handles to the following objects: This doc was truncated. Read more on docs.microsoft.com. Frees the loaded dynamic-link library (DLL) module and, if necessary, decrements its reference count. A handle to the loaded library module. The LoadLibrary, LoadLibraryEx, GetModuleHandle, or GetModuleHandleEx function returns this handle. Read more on docs.microsoft.com. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call the GetLastError function. The system maintains a per-process reference count for each loaded module. A module that was loaded at process initialization due to load-time dynamic linking has a reference count of one. The reference count for a module is incremented each time the module is loaded by a call to LoadLibrary. The reference count is also incremented by a call to LoadLibraryEx unless the module is being loaded for the first time and is being loaded as a data or image file. The reference count is decremented each time the FreeLibrary or FreeLibraryAndExitThread function is called for the module. When a module's reference count reaches zero or the process terminates, the system unloads the module from the address space of the process. Before unloading a library module, the system enables the module to detach from the process by calling the module's DllMain function, if it has one, with the DLL_PROCESS_DETACH value. Doing so gives the library module an opportunity to clean up resources allocated on behalf of the current process. After the entry-point function returns, the library module is removed from the address space of the current process. It is not safe to call FreeLibrary from DllMain. For more information, see the Remarks section in DllMain. Calling FreeLibrary does not affect other processes that are using the same module. Use caution when calling FreeLibrary with a handle returned by GetModuleHandle. The GetModuleHandle function does not increment a module's reference count, so passing this handle to FreeLibrary can cause a module to be unloaded prematurely. A thread that must unload the DLL in which it is executing and then terminate itself should call FreeLibraryAndExitThread instead of calling FreeLibrary and ExitThread separately. Otherwise, a race condition can occur. For details, see the Remarks section of FreeLibraryAndExitThread. Read more on docs.microsoft.com. Retrieves a module handle for the specified module. The module must have been loaded by the calling process. (Unicode) The name of the loaded module (either a .dll or .exe file). If the file name extension is omitted, the default library extension .dll is appended. The file name string can include a trailing point character (.) to indicate that the module name has no extension. The string does not have to specify a path. When specifying a path, be sure to use backslashes (\\), not forward slashes (/). The name is compared (case independently) to the names of modules currently mapped into the address space of the calling process. If this parameter is NULL, GetModuleHandle returns a handle to the file used to create the calling process (.exe file). The GetModuleHandle function does not retrieve handles for modules that were loaded using the LOAD_LIBRARY_AS_DATAFILE flag. For more information, see LoadLibraryEx. Read more on docs.microsoft.com. If the function succeeds, the return value is a handle to the specified module. If the function fails, the return value is NULL. To get extended error information, call GetLastError. The returned handle is not global or inheritable. It cannot be duplicated or used by another process. If lpModuleName does not include a path and there is more than one loaded module with the same base name and extension, you cannot predict which module handle will be returned. To work around this problem, you could specify a path, use side-by-side assemblies, or use GetModuleHandleEx to specify a memory location rather than a DLL name. The GetModuleHandle function returns a handle to a mapped module without incrementing its reference count. However, if this handle is passed to the FreeLibrary function, the reference count of the mapped module will be decremented. Therefore, do not pass a handle returned by GetModuleHandle to the FreeLibrary function. Doing so can cause a DLL module to be unmapped prematurely. This function must be used carefully in a multithreaded application. There is no guarantee that the module handle remains valid between the time this function returns the handle and the time it is used. For example, suppose that a thread retrieves a module handle, but before it uses the handle, a second thread frees the module. If the system loads another module, it could reuse the module handle that was recently freed. Therefore, the first thread would have a handle to a different module than the one intended. Read more on docs.microsoft.com. Frees the specified global memory object and invalidates its handle. A handle to the global memory object. This handle is returned by either the GlobalAlloc or GlobalReAlloc function. It is not safe to free memory allocated with LocalAlloc. Read more on docs.microsoft.com. If the function succeeds, the return value is NULL. If the function fails, the return value is equal to a handle to the global memory object. To get extended error information, call GetLastError. If the process examines or modifies the memory after it has been freed, heap corruption may occur or an access violation exception (EXCEPTION_ACCESS_VIOLATION) may be generated. The GlobalFree function will free a locked memory object. A locked memory object has a lock count greater than zero. The GlobalLock function locks a global memory object and increments the lock count by one. The GlobalUnlock function unlocks it and decrements the lock count by one. To get the lock count of a global memory object, use the GlobalFlags function. If an application is running under a debug version of the system, GlobalFree will issue a message that tells you that a locked object is being freed. If you are debugging the application, GlobalFree will enter a breakpoint just before freeing a locked object. This allows you to verify the intended behavior, then continue execution. Read more on docs.microsoft.com. Allocates the specified number of bytes from the heap. (GlobalAlloc) The number of bytes to allocate. If this parameter is zero and the uFlags parameter specifies GMEM_MOVEABLE, the function returns a handle to a memory object that is marked as discarded. If the function succeeds, the return value is a handle to the newly allocated memory object. If the function fails, the return value is NULL. To get extended error information, call GetLastError. Windows memory management does not provide a separate local heap and global heap. Therefore, the GlobalAlloc and LocalAlloc functions are essentially the same. The movable-memory flags GHND and GMEM_MOVABLE add unnecessary overhead and require locking to be used safely. They should be avoided unless documentation specifically states that they should be used. New applications should use the heap functions to allocate and manage memory unless the documentation specifically states that a global function should be used. For example, the global functions are still used with Dynamic Data Exchange (DDE), the clipboard functions, and OLE data objects. If the GlobalAlloc function succeeds, it allocates at least the amount of memory requested. If the actual amount allocated is greater than the amount requested, the process can use the entire amount. To determine the actual number of bytes allocated, use the GlobalSize function. If the heap does not contain sufficient free space to satisfy the request, GlobalAlloc returns NULL. Because NULL is used to indicate an error, virtual address zero is never allocated. It is, therefore, easy to detect the use of a NULL pointer. Memory allocated with this function is guaranteed to be aligned on an 8-byte boundary. To execute dynamically generated code, use the VirtualAlloc function to allocate memory and the VirtualProtect function to grant PAGE_EXECUTE access. To free the memory, use the GlobalFree function. It is not safe to free memory allocated with GlobalAlloc using LocalFree. Read more on docs.microsoft.com. Locks a global memory object and returns a pointer to the first byte of the object's memory block. A handle to the global memory object. This handle is returned by either the GlobalAlloc or GlobalReAlloc function. Read more on docs.microsoft.com. If the function succeeds, the return value is a pointer to the first byte of the memory block. If the function fails, the return value is NULL. To get extended error information, call GetLastError. The internal data structures for each memory object include a lock count that is initially zero. For movable memory objects, GlobalLock increments the count by one, and the GlobalUnlock function decrements the count by one. Each successful call that a process makes to GlobalLock for an object must be matched by a corresponding call to GlobalUnlock. Locked memory will not be moved or discarded, unless the memory object is reallocated by using the GlobalReAlloc function. The memory block of a locked memory object remains locked until its lock count is decremented to zero, at which time it can be moved or discarded. Memory objects allocated with GMEM_FIXED always have a lock count of zero. For these objects, the value of the returned pointer is equal to the value of the specified handle. If the specified memory block has been discarded or if the memory block has a zero-byte size, this function returns NULL. Discarded objects always have a lock count of zero. Read more on docs.microsoft.com. Decrements the lock count associated with a memory object that was allocated with GMEM_MOVEABLE. A handle to the global memory object. This handle is returned by either the GlobalAlloc or GlobalReAlloc function. Read more on docs.microsoft.com. If the memory object is still locked after decrementing the lock count, the return value is a nonzero value. If the memory object is unlocked after decrementing the lock count, the function returns zero and GetLastError returns NO_ERROR. If the function fails, the return value is zero and GetLastError returns a value other than NO_ERROR. The internal data structures for each memory object include a lock count that is initially zero. For movable memory objects, the GlobalLock function increments the count by one, and GlobalUnlock decrements the count by one. For each call that a process makes to GlobalLock for an object, it must eventually call GlobalUnlock. Locked memory will not be moved or discarded, unless the memory object is reallocated by using the GlobalReAlloc function. The memory block of a locked memory object remains locked until its lock count is decremented to zero, at which time it can be moved or discarded. Memory objects allocated with GMEM_FIXED always have a lock count of zero. If the specified memory block is fixed memory, this function returns TRUE. If the memory object is already unlocked, GlobalUnlock returns FALSE and GetLastError reports ERROR_NOT_LOCKED. A process should not rely on the return value to determine the number of times it must subsequently call GlobalUnlock for a memory object. Read more on docs.microsoft.com. Gets a list of Microsoft Media Foundation transforms (MFTs) that match specified search criteria. This function extends the MFTEnum function. A GUID that specifies the category of MFTs to enumerate. For a list of MFT categories, see MFT_CATEGORY. The bitwise OR of zero or more flags from the _MFT_ENUM_FLAG enumeration. A pointer to an MFT_REGISTER_TYPE_INFO structure that specifies an input media type to match. This parameter can be NULL. If NULL, all input types are matched. Read more on docs.microsoft.com. A pointer to an MFT_REGISTER_TYPE_INFO structure that specifies an output media type to match. This parameter can be NULL. If NULL, all output types are matched. Read more on docs.microsoft.com. Receives an array of IMFActivate interface pointers. Each pointer represents an activation object for an MFT that matches the search criteria. The function allocates the memory for the array. The caller must release the pointers and call the CoTaskMemFree function to free the memory for the array. Receives the number of elements in the pppMFTActivate array. If no MFTs match the search criteria, this parameter receives the value zero. If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code. The Flags parameter controls which MFTs are enumerated, and the order in which they are returned. The flags for this parameter fall into several groups. The first set of flags specifies how an MFT processes data. This doc was truncated. Read more on docs.microsoft.com. Deallocates a string allocated previously by SysAllocString, SysAllocStringByteLen, SysReAllocString, SysAllocStringLen, or SysReAllocStringLen. The previously allocated string. If this parameter is NULL, the function simply returns. Learn more about this API from docs.microsoft.com. Sends an appbar message to the system. Type: DWORD Type: PAPPBARDATA A pointer to an APPBARDATA structure. The content of the structure on entry and on exit depends on the value set in the dwMessage parameter. See the individual message pages for specifics. Read more on docs.microsoft.com. Type: UINT_PTR This function returns a message-dependent value. For more information, see the Windows SDK documentation for the specific appbar message sent. Links to those documents are given in the See Also section. Learn more about this API from docs.microsoft.com. Opens the clipboard for examination and prevents other applications from modifying the clipboard content. Type: HWND A handle to the window to be associated with the open clipboard. If this parameter is NULL, the open clipboard is associated with the current task. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. OpenClipboard fails if another window has the clipboard open. An application should call the CloseClipboard function after every successful call to OpenClipboard. The window identified by the hWndNewOwner parameter does not become the clipboard owner unless the EmptyClipboard function is called. If an application calls OpenClipboard with hwnd set to NULL, EmptyClipboard sets the clipboard owner to NULL; this causes SetClipboardData to fail. Read more on docs.microsoft.com. Closes the clipboard. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. When the window has finished examining or changing the clipboard, close the clipboard by calling CloseClipboard. This enables other windows to access the clipboard. Do not place an object on the clipboard after calling CloseClipboard. Read more on docs.microsoft.com. Empties the clipboard and frees handles to data in the clipboard. The function then assigns ownership of the clipboard to the window that currently has the clipboard open. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. Before calling EmptyClipboard, an application must open the clipboard by using the OpenClipboard function. If the application specifies a NULL window handle when opening the clipboard, EmptyClipboard succeeds but sets the clipboard owner to NULL. Note that this causes SetClipboardData to fail. Retrieves a handle to a window whose class name and window name match the specified strings. The function searches child windows, beginning with the one following the specified child window. This function does not perform a case-sensitive search. (Unicode) Type: HWND A handle to the parent window whose child windows are to be searched. If hwndParent is NULL, the function uses the desktop window as the parent window. The function searches among windows that are child windows of the desktop. If hwndParent is HWND_MESSAGE, the function searches all message-only windows. Read more on docs.microsoft.com. Type: HWND A handle to a child window. The search begins with the next child window in the Z order. The child window must be a direct child window of hwndParent, not just a descendant window. If hwndChildAfter is NULL, the search begins with the first child window of hwndParent. Note that if both hwndParent and hwndChildAfter are NULL, the function searches all top-level and message-only windows. Read more on docs.microsoft.com. Type: LPCTSTR The class name or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be placed in the low-order word of lpszClass; the high-order word must be zero. If lpszClass is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names, or it can be MAKEINTATOM(0x8000). In this latter case, 0x8000 is the atom for a menu class. For more information, see the Remarks section of this topic. Read more on docs.microsoft.com. Type: LPCTSTR The window name (the window's title). If this parameter is NULL, all window names match. Read more on docs.microsoft.com. Type: HWND If the function succeeds, the return value is a handle to the window that has the specified class and window names. If the function fails, the return value is NULL. To get extended error information, call GetLastError. The FindWindowEx function searches only direct child windows. It does not search other descendants. If the lpszWindow parameter is not NULL, FindWindowEx calls the GetWindowText function to retrieve the window name for comparison. For a description of a potential problem that can arise, see the Remarks section of GetWindowText. An application can call this function in the following way. FindWindowEx( NULL, NULL, MAKEINTATOM(0x8000), NULL ); Note that 0x8000 is the atom for a menu class. When an application calls this function, the function checks whether a context menu is being displayed that the application created. > [!NOTE] > The winuser.h header defines FindWindowEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com. Destroys the specified menu and frees any memory that the menu occupies. Type: HMENU A handle to the menu to be destroyed. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. Before closing, an application must use the DestroyMenu function to destroy a menu not assigned to a window. A menu that is assigned to a window is automatically destroyed when the application closes. DestroyMenu is recursive, that is, it will destroy the menu and all its submenus. Read more on docs.microsoft.com. Creates an overlapped, pop-up, or child window with an extended window style; otherwise, this function is identical to the CreateWindow function. (Unicode) Type: DWORD The extended window style of the window being created. For a list of possible values, see Extended Window Styles. Read more on docs.microsoft.com. Type: LPCTSTR A null-terminated string or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero. If lpClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, provided that the module that registers the class is also the module that creates the window. The class name can also be any of the predefined system class names. Read more on docs.microsoft.com. Type: LPCTSTR The window name. If the window style specifies a title bar, the window title pointed to by lpWindowName is displayed in the title bar. When using CreateWindow to create controls, such as buttons, check boxes, and static controls, use lpWindowName to specify the text of the control. When creating a static control with the SS_ICON style, use lpWindowName to specify the icon name or identifier. To specify an identifier, use the syntax "#num". Read more on docs.microsoft.com. Type: DWORD The style of the window being created. This parameter can be a combination of the window style values, plus the control styles indicated in the Remarks section. Read more on docs.microsoft.com. Type: int The initial horizontal position of the window. For an overlapped or pop-up window, the x parameter is the initial x-coordinate of the window's upper-left corner, in screen coordinates. For a child window, x is the x-coordinate of the upper-left corner of the window relative to the upper-left corner of the parent window's client area. If x is set to CW_USEDEFAULT, the system selects the default position for the window's upper-left corner and ignores the y parameter. CW_USEDEFAULT is valid only for overlapped windows; if it is specified for a pop-up or child window, the x and y parameters are set to zero. Read more on docs.microsoft.com. Type: int The initial vertical position of the window. For an overlapped or pop-up window, the y parameter is the initial y-coordinate of the window's upper-left corner, in screen coordinates. For a child window, y is the initial y-coordinate of the upper-left corner of the child window relative to the upper-left corner of the parent window's client area. For a list box y is the initial y-coordinate of the upper-left corner of the list box's client area relative to the upper-left corner of the parent window's client area. If an overlapped window is created with the WS_VISIBLE style bit set and the x parameter is set to CW_USEDEFAULT, then the y parameter determines how the window is shown. If the y parameter is CW_USEDEFAULT, then the window manager calls ShowWindow with the SW_SHOW flag after the window has been created. If the y parameter is some other value, then the window manager calls ShowWindow with that value as the nCmdShow parameter. Read more on docs.microsoft.com. Type: int The width, in device units, of the window. For overlapped windows, nWidth is the window's width, in screen coordinates, or CW_USEDEFAULT. If nWidth is CW_USEDEFAULT, the system selects a default width and height for the window; the default width extends from the initial x-coordinates to the right edge of the screen; the default height extends from the initial y-coordinate to the top of the icon area. CW_USEDEFAULT is valid only for overlapped windows; if CW_USEDEFAULT is specified for a pop-up or child window, the nWidth and nHeight parameter are set to zero. Read more on docs.microsoft.com. Type: int The height, in device units, of the window. For overlapped windows, nHeight is the window's height, in screen coordinates. If the nWidth parameter is set to CW_USEDEFAULT, the system ignores nHeight. Read more on docs.microsoft.com. Type: HWND A handle to the parent or owner window of the window being created. To create a child window or an owned window, supply a valid window handle. This parameter is optional for pop-up windows. To create a message-only window, supply HWND_MESSAGE or a handle to an existing message-only window. Read more on docs.microsoft.com. Type: HMENU A handle to a menu, or specifies a child-window identifier, depending on the window style. For an overlapped or pop-up window, hMenu identifies the menu to be used with the window; it can be NULL if the class menu is to be used. For a child window, hMenu specifies the child-window identifier, an integer value used by a dialog box control to notify its parent about events. The application determines the child-window identifier; it must be unique for all child windows with the same parent window. Read more on docs.microsoft.com. Type: HINSTANCE A handle to the instance of the module to be associated with the window. Read more on docs.microsoft.com. Type: LPVOID Pointer to a value to be passed to the window through the CREATESTRUCT structure (lpCreateParams member) pointed to by the lParam param of the WM_CREATE message. This message is sent to the created window by this function before it returns. If an application calls CreateWindow to create a MDI client window, lpParam should point to a CLIENTCREATESTRUCT structure. If an MDI client window calls CreateWindow to create an MDI child window, lpParam should point to a MDICREATESTRUCT structure. lpParam may be NULL if no additional data is needed. Read more on docs.microsoft.com. Type: HWND If the function succeeds, the return value is a handle to the new window. If the function fails, the return value is NULL. To get extended error information, call GetLastError. This function typically fails for one of the following reasons: This doc was truncated. The CreateWindowEx function sends WM_NCCREATE, WM_NCCALCSIZE, and WM_CREATE messages to the window being created. If the created window is a child window, its default position is at the bottom of the Z-order. If the created window is a top-level window, its default position is at the top of the Z-order (but beneath all topmost windows unless the created window is itself topmost). For information on controlling whether the Taskbar displays a button for the created window, see Managing Taskbar Buttons. For information on removing a window, see the DestroyWindow function. The following predefined control classes can be specified in the lpClassName parameter. Note the corresponding control styles you can use in the dwStyle parameter. This doc was truncated. Read more on docs.microsoft.com. Destroys the specified window. Type: HWND A handle to the window to be destroyed. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. A thread cannot use DestroyWindow to destroy a window created by a different thread. If the window being destroyed is a child window that does not have the WS_EX_NOPARENTNOTIFY style, a WM_PARENTNOTIFY message is sent to the parent. Read more on docs.microsoft.com. Destroys an icon and frees any memory the icon occupied. Type: HICON A handle to the icon to be destroyed. The icon must not be in use. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. It is only necessary to call DestroyIcon for icons and cursors created with the following functions: CreateIconFromResourceEx (if called without the LR_SHARED flag), CreateIconIndirect, and CopyIcon. Do not use this function to destroy a shared icon. A shared icon is valid as long as the module from which it was loaded remains in memory. The following functions obtain a shared icon. This doc was truncated. Read more on docs.microsoft.com. Destroys a cursor and frees any memory the cursor occupied. Do not use this function to destroy a shared cursor. Type: HCURSOR A handle to the cursor to be destroyed. The cursor must not be in use. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. The DestroyCursor function destroys a nonshared cursor. Do not use this function to destroy a shared cursor. A shared cursor is valid as long as the module from which it was loaded remains in memory. The following functions obtain a shared cursor: This doc was truncated. Read more on docs.microsoft.com. Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassExW) Type: ATOM If the function succeeds, the return value is a class atom that uniquely identifies the class being registered. This atom can only be used by the CreateWindow, CreateWindowEx, GetClassInfo, GetClassInfoEx, FindWindow, FindWindowEx, and UnregisterClass functions and the IActiveIMMap::FilterClientWindows method. If the function fails, the return value is zero. To get extended error information, call GetLastError. If you register the window class by using RegisterClassExA, the application tells the system that the windows of the created class expect messages with text or character parameters to use the ANSI character set; if you register it by using RegisterClassExW, the application requests that the system pass text parameters of messages as Unicode. The IsWindowUnicode function enables applications to query the nature of each window. For more information on ANSI and Unicode functions, see Conventions for Function Prototypes. All window classes that an application registers are unregistered when it terminates. No window classes registered by a DLL are unregistered when the DLL is unloaded. A DLL must explicitly unregister its classes when it is unloaded. Read more on docs.microsoft.com. Unregisters a window class, freeing the memory required for the class. (Unicode) Type: LPCTSTR A null-terminated string or a class atom. If lpClassName is a string, it specifies the window class name. This class name must have been registered by a previous call to the RegisterClass or RegisterClassEx function. System classes, such as dialog box controls, cannot be unregistered. If this parameter is an atom, it must be a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero. Read more on docs.microsoft.com. Type: HINSTANCE A handle to the instance of the module that created the class. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the class could not be found or if a window still exists that was created with the class, the return value is zero. To get extended error information, call GetLastError. Before calling this function, an application must destroy all windows created with the specified class. All window classes that an application registers are unregistered when it terminates. Class atoms are special atoms returned only by RegisterClass and RegisterClassEx. No window classes registered by a DLL are unregistered when the .dll is unloaded. > [!NOTE] > The winuser.h header defines UnregisterClass as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com. Places (posts) a message in the message queue associated with the thread that created the specified window and returns without waiting for the thread to process the message. (Unicode) Type: HWND A handle to the window whose window procedure is to receive the message. The following values have special meanings. This doc was truncated. Read more on docs.microsoft.com. Type: UINT The message to be posted. For lists of the system-provided messages, see System-Defined Messages. Read more on docs.microsoft.com. Type: WPARAM Additional message-specific information. Read more on docs.microsoft.com. Type: LPARAM Additional message-specific information. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. When a message is blocked by UIPI the last error, retrieved with GetLastError, is set to 5 (access denied). Messages in a message queue are retrieved by calls to the GetMessage or PeekMessage function. Applications that need to communicate using HWND_BROADCAST should use the RegisterWindowMessage function to obtain a unique message for inter-application communication. The system only does marshalling for system messages (those in the range 0 to (WM_USER-1)). To send other messages (those >= WM_USER) to another process, you must do custom marshalling. If you send a message in the range below WM_USER to the asynchronous message functions (PostMessage, SendNotifyMessage, and SendMessageCallback), its message parameters cannot include pointers. Otherwise, the operation will fail. The functions will return before the receiving thread has had a chance to process the message and the sender will free the memory before it is used. Do not post the WM_QUIT message using PostMessage; use the PostQuitMessage function. An accessibility application can use PostMessage to post WM_APPCOMMAND messages to the shell to launch applications. This functionality is not guaranteed to work for other types of applications. There is a limit of 10,000 posted messages per message queue. This limit should be sufficiently large. If your application exceeds the limit, it should be redesigned to avoid consuming so many system resources. To adjust this limit, modify the following registry key. 
HKEY_LOCAL_MACHINE SOFTWARE Microsoft Windows NT CurrentVersion Windows USERPostMessageLimit
If the function fails, call GetLastError to get extended error information. GetLastError returns ERROR_NOT_ENOUGH_QUOTA when the limit is hit. The minimum acceptable value is 4000. Read more on docs.microsoft.com. Calls the default window procedure to provide default processing for any window messages that an application does not process. (Unicode) Type: HWND A handle to the window procedure that received the message. Read more on docs.microsoft.com. Type: UINT The message. Read more on docs.microsoft.com. Type: WPARAM Additional message information. The content of this parameter depends on the value of the Msg parameter. Read more on docs.microsoft.com. Type: LPARAM Additional message information. The content of this parameter depends on the value of the Msg parameter. Read more on docs.microsoft.com. Type: LRESULT The return value is the result of the message processing and depends on the message. > [!NOTE] > The winuser.h header defines DefWindowProc as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com. Places data on the clipboard in a specified clipboard format. Type: UINT The clipboard format. This parameter can be a registered format or any of the standard clipboard formats. For more information, see Standard Clipboard Formats and Registered Clipboard Formats. Read more on docs.microsoft.com. Type: HANDLE A handle to the data in the specified format. This parameter can be NULL, indicating that the window provides data in the specified clipboard format (renders the format) upon request; this is known as [delayed rendering](/windows/win32/dataxchg/clipboard-operations#delayed-rendering). If a window delays rendering, it must process the [WM_RENDERFORMAT](/windows/win32/dataxchg/wm-renderformat) and [WM_RENDERALLFORMATS](/windows/win32/dataxchg/wm-renderallformats) messages. If SetClipboardData succeeds, the system owns the object identified by the hMem parameter. The application may not write to or free the data once ownership has been transferred to the system, but it can lock and read from the data until the CloseClipboard function is called. (The memory must be unlocked before the Clipboard is closed.) If the hMem parameter identifies a memory object, the object must have been allocated using the function with the GMEM_MOVEABLE flag. Read more on docs.microsoft.com. Type: HANDLE If the function succeeds, the return value is the handle to the data. If the function fails, the return value is NULL. To get extended error information, call GetLastError. Windows 8: Bitmaps to be shared with Windows Store app apps must be in the CF_BITMAP format (device-dependent bitmap). If an application calls SetClipboardData in response to WM_RENDERFORMAT or WM_RENDERALLFORMATS, the application should not use the handle after SetClipboardData has been called. If an application calls OpenClipboard with hwnd set to NULL, EmptyClipboard sets the clipboard owner to NULL; this causes SetClipboardData to fail. The system performs implicit data format conversions between certain clipboard formats when an application calls the GetClipboardData function. For example, if the CF_OEMTEXT format is on the clipboard, a window can retrieve data in the CF_TEXT format. The format on the clipboard is converted to the requested format on demand. For more information, see Synthesized Clipboard Formats. Read more on docs.microsoft.com. Creates a new image (icon, cursor, or bitmap) and copies the attributes of the specified image to the new one. If necessary, the function stretches the bits to fit the desired size of the new image. Type: HANDLE A handle to the image to be copied. Read more on docs.microsoft.com. Type: UINT Type: int The desired width, in pixels, of the image. If this is zero, then the returned image will have the same width as the original hImage. Read more on docs.microsoft.com. Type: int The desired height, in pixels, of the image. If this is zero, then the returned image will have the same height as the original hImage. Read more on docs.microsoft.com. Type: UINT Type: HANDLE If the function succeeds, the return value is the handle to the newly created image. If the function fails, the return value is NULL. To get extended error information, call GetLastError. When you are finished using the resource, you can release its associated memory by calling one of the functions in the following table. This doc was truncated. Read more on docs.microsoft.com. Enumerates the data formats currently available on the clipboard. Type: UINT A clipboard format that is known to be available. To start an enumeration of clipboard formats, set format to zero. When format is zero, the function retrieves the first available clipboard format. For subsequent calls during an enumeration, set format to the result of the previous EnumClipboardFormats call. Read more on docs.microsoft.com. Type: UINT If the function succeeds, the return value is the clipboard format that follows the specified format, namely the next available clipboard format. If the function fails, the return value is zero. To get extended error information, call GetLastError. If the clipboard is not open, the function fails. If there are no more clipboard formats to enumerate, the return value is zero. In this case, the GetLastError function returns the value ERROR_SUCCESS. This lets you distinguish between function failure and the end of enumeration. You must open the clipboard before enumerating its formats. Use the OpenClipboard function to open the clipboard. The EnumClipboardFormats function fails if the clipboard is not open. The EnumClipboardFormats function enumerates formats in the order that they were placed on the clipboard. If you are copying information to the clipboard, add clipboard objects in order from the most descriptive clipboard format to the least descriptive clipboard format. If you are pasting information from the clipboard, retrieve the first clipboard format that you can handle. That will be the most descriptive clipboard format that you can handle. The system provides automatic type conversions for certain clipboard formats. In the case of such a format, this function enumerates the specified format, then enumerates the formats to which it can be converted. For more information, see Standard Clipboard Formats and Synthesized Clipboard Formats. Read more on docs.microsoft.com. Retrieves from the clipboard the name of the specified registered format. The function copies the name to the specified buffer. (Unicode) Type: UINT The type of format to be retrieved. This parameter must not specify any of the predefined clipboard formats. Read more on docs.microsoft.com. Type: LPTSTR The buffer that is to receive the format name. Read more on docs.microsoft.com. Type: int The maximum length, in characters, of the string to be copied to the buffer. If the name exceeds this limit, it is truncated. Read more on docs.microsoft.com. Type: int If the function succeeds, the return value is the length, in characters, of the string copied to the buffer. If the function fails, the return value is zero, indicating that the requested format does not exist or is predefined. To get extended error information, call GetLastError.

Security Considerations

Using this function incorrectly might compromise the security of your program. For example, miscalculating the proper size of the lpszFormatName buffer, especially when the application is used in both ANSI and Unicode versions, can cause a buffer overflow. Also, note that the string is truncated if it is longer than the cchMaxCount parameter, which can lead to loss of information. Read more on docs.microsoft.com. Registers a new clipboard format. This format can then be used as a valid clipboard format. (Unicode) Type: LPCTSTR The name of the new format. Read more on docs.microsoft.com. Type: UINT If the function succeeds, the return value identifies the registered clipboard format. If the function fails, the return value is zero. To get extended error information, call GetLastError. If a registered format with the specified name already exists, a new format is not registered and the return value identifies the existing format. This enables more than one application to copy and paste data using the same registered clipboard format. Note that the format name comparison is case-insensitive. Registered clipboard formats are identified by values in the range 0xC000 through 0xFFFF. When registered clipboard formats are placed on or retrieved from the clipboard, they must be in the form of an HGLOBAL value. Read more on docs.microsoft.com. Retrieves the window handle of the current owner of the clipboard. Type: HWND If the function succeeds, the return value is the handle to the window that owns the clipboard. If the clipboard is not owned, the return value is NULL. To get extended error information, call GetLastError. The clipboard can still contain data even if the clipboard is not currently owned. In general, the clipboard owner is the window that last placed data in clipboard. The EmptyClipboard function assigns clipboard ownership. Read more on docs.microsoft.com. Determines whether the clipboard contains data in the specified format. Type: UINT A standard or registered clipboard format. For a description of the standard clipboard formats, see Standard Clipboard Formats . Read more on docs.microsoft.com. Type: BOOL If the clipboard format is available, the return value is nonzero. If the clipboard format is not available, the return value is zero. To get extended error information, call GetLastError. Typically, an application that recognizes only one clipboard format would call this function when processing the WM_INITMENU or WM_INITMENUPOPUP message. The application would then enable or disable the Paste menu item, depending on the return value. Applications that recognize more than one clipboard format should use the GetPriorityClipboardFormat function for this purpose. Retrieves data from the clipboard in a specified format. The clipboard must have been opened previously. Type: UINT A clipboard format. For a description of the standard clipboard formats, see Standard Clipboard Formats. Read more on docs.microsoft.com. Type: HANDLE If the function succeeds, the return value is the handle to a clipboard object in the specified format. If the function fails, the return value is NULL. To get extended error information, call GetLastError.
Caution  Clipboard data is not trusted. Parse the data carefully before using it in your application.
 
An application can enumerate the available formats in advance by using the EnumClipboardFormats function. The clipboard controls the handle that the GetClipboardData function returns, not the application. The application should copy the data immediately. The application must not free the handle nor leave it locked. The application must not use the handle after the EmptyClipboard or CloseClipboard function is called, or after the SetClipboardData function is called with the same clipboard format. The system performs implicit data format conversions between certain clipboard formats when an application calls the GetClipboardData function. For example, if the CF_OEMTEXT format is on the clipboard, a window can retrieve data in the CF_TEXT format. The format on the clipboard is converted to the requested format on demand. For more information, see Synthesized Clipboard Formats. Read more on docs.microsoft.com. Places the given window in the system-maintained clipboard format listener list. Type: HWND A handle to the window to be placed in the clipboard format listener list. Read more on docs.microsoft.com. Type: BOOL Returns TRUE if successful, FALSE otherwise. Call GetLastError for additional details. When a window has been added to the clipboard format listener list, it is posted a WM_CLIPBOARDUPDATE message whenever the contents of the clipboard have changed. Removes the given window from the system-maintained clipboard format listener list. Type: HWND A handle to the window to remove from the clipboard format listener list. Read more on docs.microsoft.com. Type: BOOL Returns TRUE if successful, FALSE otherwise. Call GetLastError for additional details. When a window has been removed from the clipboard format listener list, it will no longer receive WM_CLIPBOARDUPDATE messages. Enables the specified process to set the foreground window using the SetForegroundWindow function. The calling process must already be able to set the foreground window. For more information, see Remarks later in this topic. Type: DWORD The identifier of the process that will be enabled to set the foreground window. If this parameter is ASFW_ANY, all processes will be enabled to set the foreground window. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. The function will fail if the calling process cannot set the foreground window. To get extended error information, call GetLastError. The system restricts which processes can set the foreground window. Normally, a process can set the foreground window by calling the [**SetForegroundWindow**](nf-winuser-setforegroundwindow.md) function only if: - All of the following conditions are true: - The calling process belongs to a desktop application, not a UWP app or a Windows Store app designed for Windows 8 or 8.1. - The foreground process has not disabled calls to **SetForegroundWindow** by a previous call to the [**LockSetForegroundWindow**](nf-winuser-locksetforegroundwindow.md) function. - The foreground lock time-out has expired (see [**SPI_GETFOREGROUNDLOCKTIMEOUT** in **SystemParametersInfo**](nf-winuser-systemparametersinfoa.md#SPI_GETFOREGROUNDLOCKTIMEOUT)). - No menus are active. - Additionally, at least one of the following conditions is true: - The calling process is the foreground process. - The calling process was started by the foreground process. - There is currently no foreground window, and thus no foreground process. - The calling process received the last input event. - Either the foreground process or the calling process is being debugged. A process that can set the foreground window can enable another process to set the foreground window by calling **AllowSetForegroundWindow**. The process specified by the *dwProcessId* parameter loses the ability to set the foreground window the next time that either the user generates input, unless the input is directed at that process, or the next time a process calls **AllowSetForegroundWindow**, unless the same process is specified as in the previous call to **AllowSetForegroundWindow**. Read more on docs.microsoft.com. The MonitorFromPoint function retrieves a handle to the display monitor that contains a specified point. A POINT structure that specifies the point of interest in virtual-screen coordinates. Determines the function's return value if the point is not contained within any display monitor. If the point is contained by a display monitor, the return value is an HMONITOR handle to that display monitor. If the point is not contained by a display monitor, the return value depends on the value of dwFlags. Learn more about this API from docs.microsoft.com. The GetMonitorInfo function retrieves information about a display monitor. (Unicode) A handle to the display monitor of interest. A pointer to a MONITORINFO or MONITORINFOEX structure that receives information about the specified display monitor. You must set the cbSize member of the structure to sizeof(MONITORINFO) or sizeof(MONITORINFOEX) before calling the GetMonitorInfo function. Doing so lets the function determine the type of structure you are passing to it. The MONITORINFOEX structure is a superset of the MONITORINFO structure. It has one additional member: a string that contains a name for the display monitor. Most applications have no use for a display monitor name, and so can save some bytes by using a MONITORINFO structure. Read more on docs.microsoft.com. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. > [!NOTE] > The winuser.h header defines GetMonitorInfo as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com. Retrieves the specified system metric or system configuration setting. Type: int Type: int If the function succeeds, the return value is the requested system metric or configuration setting. If the function fails, the return value is 0. GetLastError does not provide extended error information. System metrics can vary from display to display. GetSystemMetrics(SM_CMONITORS) counts only visible display monitors. This is different from EnumDisplayMonitors, which enumerates both visible display monitors and invisible pseudo-monitors that are associated with mirroring drivers. An invisible pseudo-monitor is associated with a pseudo-device used to mirror application drawing for remoting or other purposes. The SM_ARRANGE setting specifies how the system arranges minimized windows, and consists of a starting position and a direction. The starting position can be one of the following values. This doc was truncated. Read more on docs.microsoft.com. Retrieves the specified system metric or system configuration setting taking into account a provided DPI. The system metric or configuration setting to be retrieved. See GetSystemMetrics for the possible values. The DPI to use for scaling the metric. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. This function returns the same result as GetSystemMetrics but scales it according to an arbitrary DPI you provide if appropriate. The GetDC function retrieves a handle to a device context (DC) for the client area of a specified window or for the entire screen. A handle to the window whose DC is to be retrieved. If this value is NULL, GetDC retrieves the DC for the entire screen. If the function succeeds, the return value is a handle to the DC for the specified window's client area. If the function fails, the return value is NULL. The GetDC function retrieves a common, class, or private DC depending on the class style of the specified window. For class and private DCs, GetDC leaves the previously assigned attributes unchanged. However, for common DCs, GetDC assigns default attributes to the DC each time it is retrieved. For example, the default font is System, which is a bitmap font. Because of this, the handle to a common DC returned by GetDC does not tell you what font, color, or brush was used when the window was drawn. To determine the font, call GetTextFace. Note that the handle to the DC can only be used by a single thread at any one time. After painting with a common DC, the ReleaseDC function must be called to release the DC. Class and private DCs do not have to be released. ReleaseDC must be called from the same thread that called GetDC. The number of DCs is limited only by available memory. Read more on docs.microsoft.com. The ReleaseDC function releases a device context (DC), freeing it for use by other applications. The effect of the ReleaseDC function depends on the type of DC. It frees only common and window DCs. It has no effect on class or private DCs. A handle to the window whose DC is to be released. A handle to the DC to be released. The return value indicates whether the DC was released. If the DC was released, the return value is 1. If the DC was not released, the return value is zero. The application must call the ReleaseDC function for each call to the GetWindowDC function and for each call to the GetDC function that retrieves a common DC. An application cannot use the ReleaseDC function to release a DC that was created by calling the CreateDC function; instead, it must use the DeleteDC function. ReleaseDC must be called from the same thread that called GetDC. Read more on docs.microsoft.com. Represents a Win32 handle that can be closed with .