Extensions Class (System.Xml.Schema)

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.NET Framework Class Library
Extensions Class

This class contains the LINQ to XML extension methods for XSD validation.

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

Visual Basic (Declaration)
<ExtensionAttribute> _
Public NotInheritable Class Extensions
Visual Basic (Usage)
You do not need to declare an instance of a static class in order to access its members.
C#
public static class Extensions
Visual C++
[ExtensionAttribute]
public ref class Extensions abstract sealed
JScript
public final class Extensions
Remarks

This class also contains methods to get the post-schema-validation infoset (PSVI) of a validated XML node.

When you validate an XDocument, XElement, or XAttribute, you can also optionally populate the XML tree with the post-schema-validation infoset. PSVI information is added as an annotation of type System.Xml.Schema.XmlSchemaInfo.

Examples

The XSD in Sample XSD File: Customers and Orders contains a schema that can be used to validate the XML document in Sample XML File: Customers and Orders (LINQ to XML). The following example loads the schema and the document, validates the document, changes the document so that the xs:key and xs:keyref relationship is not valid, and then attempts to validate again.

C#
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add("", "CustomersOrders.xsd");

XDocument custOrd = XDocument.Load("CustomersOrders.xml");

Console.WriteLine("Validating custOrd");
bool errors = false;
custOrd.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("custOrd {0}", errors ? "did not validate" : "validated");

// Modify the custOrd tree so that it is no longer valid.
custOrd.Root.Element("Orders").Element("Order").Element("CustomerID").Value = "AAAAA";

Console.WriteLine();
Console.WriteLine("Validating custOrd");
errors = false;
custOrd.Validate(schemas, (o, e) =>
                     {
                         Console.WriteLine("{0}", e.Message);
                         errors = true;
                     });
Console.WriteLine("custOrd {0}", errors ? "did not validate" : "validated");
Visual Basic
Dim errors As Boolean = False

Private Sub XSDErrors(ByVal o As Object, ByVal e As ValidationEventArgs)
    Console.WriteLine("{0}", e.Message)
    errors = True
End Sub

Sub Main()
    Dim schemas As XmlSchemaSet = New XmlSchemaSet()
    schemas.Add("", "CustomersOrders.xsd")

    Console.WriteLine("Validating custOrd")
    Dim custOrd As XDocument = XDocument.Load("CustomersOrders.xml")
    errors = False
    custOrd.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("custOrd {0}", IIf(errors, "did not validate", "validated"))

    Console.WriteLine()
    Console.WriteLine("Validating custOrd")
    ' Modify the source document so that it will not validate.
    custOrd.Root.Element("Orders").Element("Order").Element("CustomerID").Value = "AAAAA"
    errors = False
    custOrd.Validate(schemas, AddressOf XSDErrors)
    Console.WriteLine("custOrd {0}", IIf(errors, "did not validate", "validated"))
End Sub

This example produces the following output:

Validating custOrd
custOrd validated

Validating custOrd
The key sequence 'AAAAA' in Keyref fails to refer to some key.
custOrd did not validate
Inheritance Hierarchy

System.Object
  System.Xml.Schema.Extensions
Thread Safety

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

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

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.
Version Information

.NET Framework

Supported in: 3.5
See Also

Reference