How Do I...Validate an XML Document?

This sample illustrates how to validate an XML document by using a validating XML reader and the Validate method of the XmlDocument class. A validating XML reader is used to create the XmlDocument object that contains the XML document to validate. The XmlReaderSettings object used to create the validating XmlReader object contains the schema used to validate the XML document, and specifies the ValidationEventHandler used to handle schema validation warnings and errors.

The following code creates the XmlReaderSettings object.

XmlReaderSettings settings = new XmlReaderSettings(); settings.Schemas.Add("urn:xmlns:25hoursaday-com:my-bookshelf", xsd); settings.ValidationEventHandler += new ValidationEventHandler(ValidationCallback); settings.ValidationType = ValidationType.Schema; Dim settings As New XmlReaderSettings() settings.Schemas.Add("urn:xmlns:25hoursaday-com:my-bookshelf", xsd) AddHandler settings.ValidationEventHandler, AddressOf ValidationCallback settings.ValidationType = ValidationType.Schema

The following code creates the validating XmlReader object and the XmlDocument object.

XmlDocument doc = new XmlDocument(); doc.Load(XmlReader.Create(document, settings)); Dim doc As New XmlDocument() doc.Load(XmlReader.Create(document, settings))

The following code validates the changes made to the XML document.

doc.Validate(new ValidationEventHandler(ValidationCallback), element.ParentNode); doc.Validate(New ValidationEventHandler(AddressOf ValidationCallback), element.ParentNode)