XmlSchemaKeyref Classe

Riferimento

Definizione

Spazio dei nomi:: System.Xml.Schema

Assembly:: System.Xml.ReaderWriter.dll

Assembly:: System.Xml.dll

Assembly:: netstandard.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Questa classe rappresenta l'elemento keyref di XML Schema come specificato dal World Wide Web Consortium (W3C).

public ref class XmlSchemaKeyref : System::Xml::Schema::XmlSchemaIdentityConstraint

public class XmlSchemaKeyref : System.Xml.Schema.XmlSchemaIdentityConstraint

type XmlSchemaKeyref = class
    inherit XmlSchemaIdentityConstraint

Public Class XmlSchemaKeyref
Inherits XmlSchemaIdentityConstraint

Ereditarietà: Object

XmlSchemaObject

XmlSchemaAnnotated

XmlSchemaIdentityConstraint
XmlSchemaKeyref

Esempio

Nell'esempio seguente viene creato un key elemento.

#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
};

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

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
   
   
   
   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
End Class

' Main() 

'XmlSchemaObjectGenerator

Il file XML seguente viene generato per l'esempio di codice precedente.

<?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>

Commenti

Specifica che un attributo o un valore di elemento (o un set di valori) ha una corrispondenza con quelli dell'elemento o unique specificatokey. Il nome del vincolo deve essere univoco all'interno di uno schema.

Costruttori

XmlSchemaKeyref()

Inizializza una nuova istanza della classe XmlSchemaKeyref.

Proprietà

Annotation	Ottiene o imposta la proprietà `annotation`. (Ereditato da XmlSchemaAnnotated)
Fields	Ottiene l'insieme dei campi considerati figli per il selettore di espressioni di XML Path Language (XPath). (Ereditato da XmlSchemaIdentityConstraint)
Id	Ottiene o imposta l'ID di stringa. (Ereditato da XmlSchemaAnnotated)
LineNumber	Ottiene o imposta il numero di riga nel file a cui l'elemento `schema` fa riferimento. (Ereditato da XmlSchemaObject)
LinePosition	Ottiene o imposta la posizione di riga nel file a cui l'elemento `schema` fa riferimento. (Ereditato da XmlSchemaObject)
Name	Ottiene o imposta il nome del vincolo di identità. (Ereditato da XmlSchemaIdentityConstraint)
Namespaces	Ottiene o imposta l'oggetto XmlSerializerNamespaces da utilizzare con questo oggetto schema. (Ereditato da XmlSchemaObject)
Parent	Ottiene o imposta la classe padre della classe XmlSchemaObject. (Ereditato da XmlSchemaObject)
QualifiedName	Ottiene il nome completo del vincolo di identità che contiene il valore successivo alla compilazione della proprietà `QualifiedName`. (Ereditato da XmlSchemaIdentityConstraint)
Refer	Ottiene o imposta il nome della chiave a cui questo vincolo fa riferimento in un altro tipo semplice o complesso.
Selector	Ottiene o imposta l'elemento `selector` dell'espressione XPath. (Ereditato da XmlSchemaIdentityConstraint)
SourceUri	Ottiene o imposta la posizione di origine per il file che ha caricato lo schema. (Ereditato da XmlSchemaObject)
UnhandledAttributes	Ottiene o imposta gli attributi qualificati che non appartengono allo spazio dei nomi di destinazione dello schema corrente. (Ereditato da XmlSchemaAnnotated)

Metodi

Equals(Object)	Determina se l'oggetto specificato è uguale all'oggetto corrente. (Ereditato da Object)
GetHashCode()	Funge da funzione hash predefinita. (Ereditato da Object)
GetType()	Ottiene l'oggetto Type dell'istanza corrente. (Ereditato da Object)
MemberwiseClone()	Crea una copia superficiale dell'oggetto Object corrente. (Ereditato da Object)
ToString()	Restituisce una stringa che rappresenta l'oggetto corrente. (Ereditato da Object)

Si applica a