XmlSchemaKeyref-Klasse
Diese Klasse stellt das keyref-Element aus XMLSchema dar, wie vom World Wide Web Consortium (W3C) festgelegt.
Namespace: System.Xml.Schema
Assembly: System.Xml (in system.xml.dll)
Syntax
'Declaration
Public Class XmlSchemaKeyref
Inherits XmlSchemaIdentityConstraint
'Usage
Dim instance As XmlSchemaKeyref
public class XmlSchemaKeyref : XmlSchemaIdentityConstraint
public ref class XmlSchemaKeyref : public XmlSchemaIdentityConstraint
public class XmlSchemaKeyref extends XmlSchemaIdentityConstraint
public class XmlSchemaKeyref extends XmlSchemaIdentityConstraint
Hinweise
Gibt an, dass ein Attribut- oder Elementwert (oder eine Gruppe von Werten) den Werten des angegebenen key-Elements oder des unique-Elements entsprechen muss. Der Name der Einschränkung muss in einem Schema eindeutig sein.
Beispiel
Im folgenden Beispiel wird ein key-Element erstellt.
Imports System
Imports System.Collections
Imports System.IO
Imports System.Xml
Imports System.Xml.Xsl
Imports System.Xml.Schema
Public Class XmlSchemaObjectGenerator
Private Shared Sub ValidationCallback(sender As Object, args As ValidationEventArgs)
If args.Severity = XmlSeverityType.Warning Then
Console.Write("WARNING: ")
Else
If args.Severity = XmlSeverityType.Error Then
Console.Write("ERROR: ")
End If
End If
Console.WriteLine(args.Message)
End Sub 'ValidationCallback
Public Shared Sub Main()
Dim tr As New XmlTextReader("empty.xsd")
Dim schema As XmlSchema = XmlSchema.Read(tr, New ValidationEventHandler(AddressOf ValidationCallback))
schema.ElementFormDefault = XmlSchemaForm.Qualified
schema.TargetNamespace = "http://www.example.com/Report"
If (True) Then
Dim element As New XmlSchemaElement()
element.Name = "purchaseReport"
Dim element_complexType As New XmlSchemaComplexType()
Dim element_complexType_sequence As New XmlSchemaSequence()
If (True) Then
Dim element_complexType_sequence_element As New XmlSchemaElement()
element_complexType_sequence_element.Name = "region"
element_complexType_sequence_element.SchemaTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")
If (True) Then
Dim element_complexType_sequence_element_keyref As New XmlSchemaKeyref()
element_complexType_sequence_element_keyref.Name = "dummy2"
element_complexType_sequence_element_keyref.Selector = New XmlSchemaXPath()
element_complexType_sequence_element_keyref.Selector.XPath = "r:zip/r:part"
If (True) Then
Dim field As New XmlSchemaXPath()
field.XPath = "@number"
element_complexType_sequence_element_keyref.Fields.Add(field)
End If
element_complexType_sequence_element_keyref.Refer = New XmlQualifiedName("pNumKey", "http://www.example.com/Report")
element_complexType_sequence_element.Constraints.Add(element_complexType_sequence_element_keyref)
End If
element_complexType_sequence.Items.Add(element_complexType_sequence_element)
End If
element_complexType.Particle = element_complexType_sequence
If (True) Then
Dim element_complexType_attribute As New XmlSchemaAttribute()
element_complexType_attribute.Name = "periodEnding"
element_complexType_attribute.SchemaTypeName = New XmlQualifiedName("date", "http://www.w3.org/2001/XMLSchema")
element_complexType.Attributes.Add(element_complexType_attribute)
End If
element.SchemaType = element_complexType
If (True) Then
Dim element_key As New XmlSchemaKey()
element_key.Name = "pNumKey"
element_key.Selector = New XmlSchemaXPath()
element_key.Selector.XPath = "r:parts/r:part"
If (True) Then
Dim field As New XmlSchemaXPath()
field.XPath = "@number"
element_key.Fields.Add(field)
End If
element.Constraints.Add(element_key)
End If
schema.Items.Add(element)
End If
schema.Write(Console.Out)
End Sub 'Main
End Class 'XmlSchemaObjectGenerator
' Main()
'XmlSchemaObjectGenerator
using System;
using System.Collections;
using System.IO;
using System.Xml;
using System.Xml.Xsl;
using System.Xml.Schema;
public 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);
}
public static void Main() {
XmlTextReader tr = new XmlTextReader("empty.xsd");
XmlSchema schema = XmlSchema.Read(tr, new ValidationEventHandler(ValidationCallback));
schema.ElementFormDefault = XmlSchemaForm.Qualified;
schema.TargetNamespace = "http://www.example.com/Report";
{
XmlSchemaElement element = new XmlSchemaElement();
element.Name = "purchaseReport";
XmlSchemaComplexType element_complexType = new XmlSchemaComplexType();
XmlSchemaSequence element_complexType_sequence = new XmlSchemaSequence();
{
XmlSchemaElement element_complexType_sequence_element = new XmlSchemaElement();
element_complexType_sequence_element.Name = "region";
element_complexType_sequence_element.SchemaTypeName =
new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")
;
{
XmlSchemaKeyref element_complexType_sequence_element_keyref = new XmlSchemaKeyref();
element_complexType_sequence_element_keyref.Name = "dummy2";
element_complexType_sequence_element_keyref.Selector = new XmlSchemaXPath();
element_complexType_sequence_element_keyref.Selector.XPath = "r:zip/r:part";
{
XmlSchemaXPath field = new XmlSchemaXPath();
field.XPath = "@number";
element_complexType_sequence_element_keyref.Fields.Add(field);
}
element_complexType_sequence_element_keyref.Refer =
new 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 = new XmlSchemaAttribute();
element_complexType_attribute.Name = "periodEnding";
element_complexType_attribute.SchemaTypeName =
new XmlQualifiedName("date", "http://www.w3.org/2001/XMLSchema")
;
element_complexType.Attributes.Add(element_complexType_attribute);
}
element.SchemaType = element_complexType;
{
XmlSchemaKey element_key = new XmlSchemaKey();
element_key.Name = "pNumKey";
element_key.Selector = new XmlSchemaXPath();
element_key.Selector.XPath = "r:parts/r:part";
{
XmlSchemaXPath field = new XmlSchemaXPath();
field.XPath = "@number";
element_key.Fields.Add(field);
}
element.Constraints.Add(element_key);
}
schema.Items.Add(element);
}
schema.Write(Console.Out);
}/* Main() */
}
//XmlSchemaObjectGenerator
#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
};
import System.*;
import System.Collections.*;
import System.IO.*;
import System.Xml.*;
import System.Xml.Xsl.*;
import System.Xml.Schema.*;
public class XmlSchemaObjectGenerator
{
private static void ValidationCallback(Object sender,
ValidationEventArgs args)
{
if (args.get_Severity().Equals(XmlSeverityType.Warning)) {
Console.Write("WARNING: ");
}
else {
if (args.get_Severity().Equals(XmlSeverityType.Error)) {
Console.Write("ERROR: ");
}
}
Console.WriteLine(args.get_Message());
} //ValidationCallback
public static void main(String[] args)
{
XmlTextReader tr = new XmlTextReader("empty.xsd");
XmlSchema schema = XmlSchema.Read
(tr, new ValidationEventHandler(ValidationCallback));
schema.set_ElementFormDefault(XmlSchemaForm.Qualified);
schema.set_TargetNamespace("http://www.example.com/Report");
{
XmlSchemaElement element = new XmlSchemaElement();
element.set_Name("purchaseReport");
XmlSchemaComplexType elementComplexType =
new XmlSchemaComplexType();
XmlSchemaSequence elementComplexTypeSequence =
new XmlSchemaSequence();
{
XmlSchemaElement elementComplexTypeSequenceElement =
new XmlSchemaElement();
elementComplexTypeSequenceElement.set_Name("region");
elementComplexTypeSequenceElement.set_SchemaTypeName
(new XmlQualifiedName("string",
"http://www.w3.org/2001/XMLSchema"));
{
XmlSchemaKeyref
elementComplexTypeSequenceElementKeyref =
new XmlSchemaKeyref();
elementComplexTypeSequenceElementKeyref.set_Name
("dummy2");
elementComplexTypeSequenceElementKeyref.set_Selector
(new XmlSchemaXPath());
elementComplexTypeSequenceElementKeyref.get_Selector()
.set_XPath("r:zip/r:part");
{
XmlSchemaXPath field = new XmlSchemaXPath();
field.set_XPath("@number");
elementComplexTypeSequenceElementKeyref
.get_Fields().Add(field);
}
elementComplexTypeSequenceElementKeyref.set_Refer
(new XmlQualifiedName("pNumKey",
"http://www.example.com/Report"));
elementComplexTypeSequenceElement.get_Constraints()
.Add(elementComplexTypeSequenceElementKeyref);
}
elementComplexTypeSequence.get_Items().Add
(elementComplexTypeSequenceElement);
}
elementComplexType.set_Particle(elementComplexTypeSequence);
{
XmlSchemaAttribute elementComplexTypeAttribute =
new XmlSchemaAttribute();
elementComplexTypeAttribute.set_Name("periodEnding");
elementComplexTypeAttribute.set_SchemaTypeName
(new XmlQualifiedName("date",
"http://www.w3.org/2001/XMLSchema"));
elementComplexType.get_Attributes().Add
(elementComplexTypeAttribute);
}
element.set_SchemaType(elementComplexType);
{
XmlSchemaKey elementKey = new XmlSchemaKey();
elementKey.set_Name("pNumKey");
elementKey.set_Selector(new XmlSchemaXPath());
elementKey.get_Selector().set_XPath("r:parts/r:part");
{
XmlSchemaXPath field = new XmlSchemaXPath();
field.set_XPath("@number");
elementKey.get_Fields().Add(field);
}
element.get_Constraints().Add(elementKey);
}
schema.get_Items().Add(element);
}
schema.Write(Console.get_Out());
} //main
} //XmlSchemaObjectGenerator
Für das vorhergehende Codebeispiel wird die folgende XML-Datei generiert.
<?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>
Vererbungshierarchie
System.Object
System.Xml.Schema.XmlSchemaObject
System.Xml.Schema.XmlSchemaAnnotated
System.Xml.Schema.XmlSchemaIdentityConstraint
System.Xml.Schema.XmlSchemaKeyref
Threadsicherheit
Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0