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XmlSchema Class

An in-memory representation of an XML Schema as specified in the World Wide Web Consortium (W3C) XML Schema Part 1: Structures and XML Schema Part 2: Datatypes specifications.

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

'Declaration
Public Class XmlSchema _
	Inherits XmlSchemaObject
'Usage
Dim instance As XmlSchema

Security noteSecurity Note:

Exceptions raised as a result of using the XmlSchema class, such as the XmlSchemaException class may contain sensitive information that should not be exposed in untrusted scenarios. For example, the SourceUri property of an XmlSchemaException returns the URI path to the schema file that caused the exception. The SourceUri property should not be exposed in untrusted scenarios. Exceptions should be properly handled so that this sensitive information is not exposed in untrusted scenarios.

The following example creates a schema definition.

Option Explicit On
Option Strict On

Imports System
Imports System.Xml
Imports System.Xml.Schema

Class XMLSchemaExamples
    Public Shared Sub Main()
        Dim schema As New XmlSchema()

        ' <xs:element name="cat" type="xs:string"/> 
        Dim elementCat As New XmlSchemaElement()
        schema.Items.Add(elementCat)
        elementCat.Name = "cat"
        elementCat.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        ' <xs:element name="dog" type="xs:string"/> 
        Dim elementDog As New XmlSchemaElement()
        schema.Items.Add(elementDog)
        elementDog.Name = "dog"
        elementDog.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")

        ' <xs:element name="redDog" substitutionGroup="dog" /> 
        Dim elementRedDog As New XmlSchemaElement()
        schema.Items.Add(elementRedDog)
        elementRedDog.Name = "redDog"
        elementRedDog.SubstitutionGroup = New XmlQualifiedName("dog")

        ' <xs:element name="brownDog" substitutionGroup ="dog" /> 
        Dim elementBrownDog As New XmlSchemaElement()
        schema.Items.Add(elementBrownDog)
        elementBrownDog.Name = "brownDog"
        elementBrownDog.SubstitutionGroup = New XmlQualifiedName("dog")

        ' <xs:element name="pets"> 
        Dim elementPets As New XmlSchemaElement()
        schema.Items.Add(elementPets)
        elementPets.Name = "pets" 

        ' <xs:complexType> 
        Dim complexType As New XmlSchemaComplexType()
        elementPets.SchemaType = complexType

        ' <xs:choice minOccurs="0" maxOccurs="unbounded"> 
        Dim choice As New XmlSchemaChoice()
        complexType.Particle = choice
        choice.MinOccurs = 0
        choice.MaxOccursString = "unbounded" 

        ' <xs:element ref="cat"/> 
        Dim catRef As New XmlSchemaElement()
        choice.Items.Add(catRef)
        catRef.RefName = New XmlQualifiedName("cat")

        ' <xs:element ref="dog"/> 
        Dim dogRef As New XmlSchemaElement()
        choice.Items.Add(dogRef)
        dogRef.RefName = New XmlQualifiedName("dog")

        Dim schemaSet As New XmlSchemaSet()
        AddHandler schemaSet.ValidationEventHandler, AddressOf ValidationCallbackOne

        schemaSet.Add(schema)
        schemaSet.Compile()

        Dim compiledSchema As XmlSchema = Nothing 

        For Each schema1 As XmlSchema In schemaSet.Schemas()
            compiledSchema = schema1
        Next 

        Dim nsmgr As New XmlNamespaceManager(New NameTable())
        nsmgr.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema")
        compiledSchema.Write(Console.Out, nsmgr)


    End Sub 'Main


    Public Shared Sub ValidationCallbackOne(ByVal sender As Object, ByVal args As ValidationEventArgs)
        Console.WriteLine(args.Message)
    End Sub 'ValidationCallbackOne
End Class 'XMLSchemaExamples

The following XML file is generated for the preceding code example.

<?xml version="1.0" encoding="IBM437"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="cat" type="xs:string"/>
    <xs:element name="dog" type="xs:string"/>
    <xs:element name="redDog" type="xs:string" substitutionGroup="dog"/>
    <xs:element name="brownDog" type="xs:string" substitutionGroup ="dog" />

    <xs:element name="pets">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element ref="cat"/>
          <xs:element ref="dog"/>
        </xs:choice>
      </xs:complexType>
    </xs:element>
</xs:schema>

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0
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