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XmlValidatingReader Constructor (String, XmlNodeType, XmlParserContext)

Initializes a new instance of the XmlValidatingReader class with the specified values.

Namespace:  System.Xml
Assembly:  System.Xml (in System.Xml.dll)

'Declaration
Public Sub New ( _
	xmlFragment As String, _
	fragType As XmlNodeType, _
	context As XmlParserContext _
)

Parameters

xmlFragment
Type: System.String

The string containing the XML fragment to parse.

fragType
Type: System.Xml.XmlNodeType

The XmlNodeType of the XML fragment. This also determines what the fragment string can contain (see table below).

context
Type: System.Xml.XmlParserContext

The XmlParserContext in which the XML fragment is to be parsed. This includes the NameTable to use, encoding, namespace scope, current xml:lang, and xml:space scope.

ExceptionCondition
XmlException

fragType is not one of the node types listed in the table below.

NoteNote

The XmlValidatingReader class is obsolete in .NET Framework 2.0. You can create a validating XmlReader instance by using the XmlReaderSettings class and the Create method. For more information, see the Remarks section of the XmlReader reference page.

This constructor parses the given string as a fragment of XML. If the XML fragment is an element or attribute, you can bypass the root level rules for well-formed XML documents. This constructor can handle strings returned from ReadInnerXml.

The following table lists valid values for fragType and how the reader parses each of the different node types.

XmlNodeType

Fragment May Contain

Element

Any valid element content (for example, any combination of elements, comments, processing instructions, cdata, text, and entity references).

Attribute

The value of an attribute (the part inside the quotes).

Document

The contents of an entire XML document; this enforces document level rules.

If this reader will be validating by using document type definition (DTD) (that is, ValidationType is set to ValidationType.DTD or ValidationType.Auto), the XmlParserContext specified in the constructor must supply all the necessary DocumentType information.

NoteNote

It is not possible to validate a fragment by using DTD. By definition DTD requires an entire document to be loaded for validation.

If this reader will be validating by using XML-Data Reduced (XDR) or XML Schema definition language (XSD) schemas, use the Schemas property to specify the XmlSchemaCollection that contains the schemas (the XmlParserContext does not need to supply the DocumentType information).

The following example reads an XML fragment. It uses an XmlParserContext and its XmlNamespaceManager to handle namespace matching.

Imports System
Imports System.IO
Imports System.Xml

Public Class Sample

    Public Shared Sub Main()
        Dim reader As XmlTextReader = Nothing 

        Try 
            'Create the XML fragment to be parsed. 
            Dim xmlFrag As String = "<book> " & _
                                    "<title>Pride And Prejudice</title>" & _
                                    "<bk:genre>novel</bk:genre>" & _
                                    "</book>" 

            'Create the XmlNamespaceManager that is used to 
            'look up namespace information. 
            Dim nt As New NameTable()
            Dim nsmgr As New XmlNamespaceManager(nt)
            nsmgr.AddNamespace("bk", "urn:sample")

            'Create the XmlParserContext. 
            Dim context As New XmlParserContext(Nothing, nsmgr, Nothing, XmlSpace.None)

            'Implement the reader. 
            reader = New XmlTextReader(xmlFrag, XmlNodeType.Element, context)

            'Parse the XML fragment.  If they exist, display the    
            'prefix and namespace URI of each element. 
            While reader.Read()
                If reader.IsStartElement() Then 
                    If reader.Prefix = String.Empty Then
                        Console.WriteLine("<{0}>", reader.LocalName)
                    Else
                        Console.Write("<{0}:{1}>", reader.Prefix, reader.LocalName)
                        Console.WriteLine(" The namespace URI is " & reader.NamespaceURI)
                    End If 
                End If 
            End While 
        Finally 
            If Not (reader Is Nothing) Then
                reader.Close()
            End If 
        End Try 
    End Sub 'Main
End Class 'Sample 

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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