XmlSchemaChoice Class

Represents the choice element (compositor) from the XML Schema as specified by the World Wide Web Consortium (W3C). The choice allows only one of its children to appear in an instance.

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

public class XmlSchemaChoice : XmlSchemaGroupBase
public class XmlSchemaChoice extends XmlSchemaGroupBase
public class XmlSchemaChoice extends XmlSchemaGroupBase

The following example creates a choice element.

using System;
using System.Xml;
using System.Xml.Schema;

class XMLSchemaExamples
    public static void Main()

        XmlSchema schema = new XmlSchema();

        // <xs:element name="selected"/>
        XmlSchemaElement xeSelected = new XmlSchemaElement();
        xeSelected.Name = "selected";

        // <xs:element name="unselected"/>
        XmlSchemaElement xeUnselected = new XmlSchemaElement();
        xeUnselected.Name = "unselected";

        // <xs:element name="dimpled"/>
        XmlSchemaElement xeDimpled = new XmlSchemaElement();
        xeDimpled.Name = "dimpled";

        // <xs:element name="perforated"/>
        XmlSchemaElement xePerforated = new XmlSchemaElement();
        xePerforated.Name = "perforated";

        // <xs:complexType name="chadState">
        XmlSchemaComplexType chadState = new XmlSchemaComplexType();
        chadState.Name = "chadState";

        // <xs:choice minOccurs="1" maxOccurs="1">
        XmlSchemaChoice choice = new XmlSchemaChoice();
        chadState.Particle = choice;
        choice.MinOccurs = 1;
        choice.MaxOccurs = 1;

        // <xs:element ref="selected"/>
        XmlSchemaElement elementSelected = new XmlSchemaElement();
        elementSelected.RefName = new XmlQualifiedName("selected");

        // <xs:element ref="unselected"/>
        XmlSchemaElement elementUnselected = new XmlSchemaElement();
        elementUnselected.RefName = new XmlQualifiedName("unselected");

        // <xs:element ref="dimpled"/>
        XmlSchemaElement elementDimpled = new XmlSchemaElement();
        elementDimpled.RefName = new XmlQualifiedName("dimpled");

        // <xs:element ref="perforated"/>
        XmlSchemaElement elementPerforated = new XmlSchemaElement();
        elementPerforated.RefName = new XmlQualifiedName("perforated");

        XmlSchemaSet schemaSet = new XmlSchemaSet();
        schemaSet.ValidationEventHandler += new ValidationEventHandler(ValidationCallbackOne);

        XmlSchema compiledSchema = null;

        foreach (XmlSchema schema1 in schemaSet.Schemas())
            compiledSchema = schema1;

        XmlNamespaceManager nsmgr = new XmlNamespaceManager(new NameTable());
        nsmgr.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema");
        compiledSchema.Write(Console.Out, nsmgr);

    public static void ValidationCallbackOne(object sender, ValidationEventArgs args)


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="selected"/>
    <xs:element name="unselected"/>
    <xs:element name="dimpled"/>
    <xs:element name="perforated"/>
    <xs:complexType name="chadState">
        <xs:choice minOccurs="1" maxOccurs="1">
            <xs:element ref="selected"/>
            <xs:element ref="unselected"/>
            <xs:element ref="dimpled"/>
            <xs:element ref="perforated"/>

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 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0

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