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XmlSchemaKeyref Class

This class represents the keyref element from XMLSchema as specified by the .

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

public ref class XmlSchemaKeyref : public XmlSchemaIdentityConstraint

The XmlSchemaKeyref type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkXmlSchemaKeyrefInitializes a new instance of the XmlSchemaKeyref class.
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  NameDescription
Public propertySupported by the XNA FrameworkAnnotationGets or sets the annotation property. (Inherited from XmlSchemaAnnotated.)
Public propertySupported by the XNA FrameworkFieldsGets the collection of fields that apply as children for the XML Path Language (XPath) expression selector. (Inherited from XmlSchemaIdentityConstraint.)
Public propertySupported by the XNA FrameworkIdGets or sets the string id. (Inherited from XmlSchemaAnnotated.)
Public propertySupported by the XNA FrameworkLineNumberGets or sets the line number in the file to which the schema element refers. (Inherited from XmlSchemaObject.)
Public propertySupported by the XNA FrameworkLinePositionGets or sets the line position in the file to which the schema element refers. (Inherited from XmlSchemaObject.)
Public propertySupported by the XNA FrameworkNameGets or sets the name of the identity constraint. (Inherited from XmlSchemaIdentityConstraint.)
Public propertySupported by the XNA FrameworkNamespacesGets or sets the XmlSerializerNamespaces to use with this schema object. (Inherited from XmlSchemaObject.)
Public propertySupported by the XNA FrameworkParentGets or sets the parent of this XmlSchemaObject. (Inherited from XmlSchemaObject.)
Public propertySupported by the XNA FrameworkQualifiedNameGets the qualified name of the identity constraint, which holds the post-compilation value of the QualifiedName property. (Inherited from XmlSchemaIdentityConstraint.)
Public propertySupported by the XNA FrameworkReferGets or sets the name of the key that this constraint refers to in another simple or complex type.
Public propertySupported by the XNA FrameworkSelectorGets or sets the XPath expression selector element. (Inherited from XmlSchemaIdentityConstraint.)
Public propertySupported by the XNA FrameworkSourceUriGets or sets the source location for the file that loaded the schema. (Inherited from XmlSchemaObject.)
Public propertySupported by the XNA FrameworkUnhandledAttributesGets or sets the qualified attributes that do not belong to the current schema's target namespace. (Inherited from XmlSchemaAnnotated.)
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  NameDescription
Public methodSupported by the XNA FrameworkEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by the XNA FrameworkGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by the XNA FrameworkToStringReturns a string that represents the current object. (Inherited from Object.)
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Specifies that an attribute or element value (or set of values) has a correspondence with those of the specified key or unique element. The constraint name must be unique within a schema.

The following example creates a key element.


#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Xsl;
using namespace System::Xml::Schema;
public ref class XmlSchemaObjectGenerator
{
private:
    static void ValidationCallback( Object^ /*sender*/, ValidationEventArgs^ args )
    {
        if ( args->Severity == XmlSeverityType::Warning )
            Console::Write( "WARNING: " );
        else
            if ( args->Severity == XmlSeverityType::Error )
                Console::Write( "ERROR: " );

        Console::WriteLine( args->Message );
    }

    // XmlSchemaObjectGenerator
    int main()
    {
        XmlTextReader^ tr = gcnew XmlTextReader( "empty.xsd" );
        XmlSchema^ schema = XmlSchema::Read( tr, gcnew ValidationEventHandler( XmlSchemaObjectGenerator::ValidationCallback ) );
        schema->ElementFormDefault = XmlSchemaForm::Qualified;
        schema->TargetNamespace = "http://www.example.com/Report";
        {
            XmlSchemaElement^ element = gcnew XmlSchemaElement;
            element->Name = "purchaseReport";
            XmlSchemaComplexType^ element_complexType = gcnew XmlSchemaComplexType;
            XmlSchemaSequence^ element_complexType_sequence = gcnew XmlSchemaSequence;
            {
                XmlSchemaElement^ element_complexType_sequence_element = gcnew XmlSchemaElement;
                element_complexType_sequence_element->Name = "region";
                element_complexType_sequence_element->SchemaTypeName = gcnew XmlQualifiedName( "String*","http://www.w3.org/2001/XMLSchema" );
                {
                    XmlSchemaKeyref^ element_complexType_sequence_element_keyref = gcnew XmlSchemaKeyref;
                    element_complexType_sequence_element_keyref->Name = "dummy2";
                    element_complexType_sequence_element_keyref->Selector = gcnew XmlSchemaXPath;
                    element_complexType_sequence_element_keyref->Selector->XPath = "r:zip/r:part";
                    {
                        XmlSchemaXPath^ field = gcnew XmlSchemaXPath;
                        field->XPath = "@number";
                        element_complexType_sequence_element_keyref->Fields->Add( field );
                    }
                    element_complexType_sequence_element_keyref->Refer = gcnew XmlQualifiedName( "pNumKey","http://www.example.com/Report" );
                    element_complexType_sequence_element->Constraints->Add( element_complexType_sequence_element_keyref );
                }
                element_complexType_sequence->Items->Add( element_complexType_sequence_element );
            }
            element_complexType->Particle = element_complexType_sequence;
            {
                XmlSchemaAttribute^ element_complexType_attribute = gcnew XmlSchemaAttribute;
                element_complexType_attribute->Name = "periodEnding";
                element_complexType_attribute->SchemaTypeName = gcnew XmlQualifiedName( "date","http://www.w3.org/2001/XMLSchema" );
                element_complexType->Attributes->Add( element_complexType_attribute );
            }
            element->SchemaType = element_complexType;
            {
                XmlSchemaKey^ element_key = gcnew XmlSchemaKey;
                element_key->Name = "pNumKey";
                element_key->Selector = gcnew XmlSchemaXPath;
                element_key->Selector->XPath = "r:parts/r:part";
                {
                    XmlSchemaXPath^ field = gcnew XmlSchemaXPath;
                    field->XPath = "@number";
                    element_key->Fields->Add( field );
                }
                element->Constraints->Add( element_key );
            }
            schema->Items->Add( element );
        }
        schema->Write( Console::Out );

        return 0;
    } // main
};


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


<?xml version="1.0" encoding="IBM437"?>
<xs:schema xmlns:r="http://www.example.com/Report" elementFormDefault="qualified" targetNamespace="http://www.example.com/Report" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="purchaseReport">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="region" type="xs:string">
          <xs:keyref name="dummy2" refer="r:pNumKey">
            <xs:selector xpath="r:zip/r:part" />
            <xs:field xpath="@number" />
          </xs:keyref>
        </xs:element>
      </xs:sequence>
      <xs:attribute name="periodEnding" type="xs:date" />
    </xs:complexType>
    <xs:key name="pNumKey">
      <xs:selector xpath="r:parts/r:part" />
      <xs:field xpath="@number" />
    </xs:key>
  </xs:element>
</xs:schema>


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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