XmlNodeChangedEventHandler-Delegat

Artikel
08/20/2007

Stellt die Methode dar, die das NodeChanged-Ereignis, das NodeChanging-Ereignis, das NodeInserted-Ereignis, das NodeInserting-Ereignis, das NodeRemoved-Ereignis und das NodeRemoving-Ereignis behandelt.

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

Syntax

'Declaration
Public Delegate Sub XmlNodeChangedEventHandler ( _
    sender As Object, _
    e As XmlNodeChangedEventArgs _
)
'Usage
Dim instance As New XmlNodeChangedEventHandler(AddressOf HandlerMethod)

public delegate void XmlNodeChangedEventHandler (
    Object sender,
    XmlNodeChangedEventArgs e
)

public delegate void XmlNodeChangedEventHandler (
    Object^ sender, 
    XmlNodeChangedEventArgs^ e
)

/** @delegate */
public delegate void XmlNodeChangedEventHandler (
    Object sender, 
    XmlNodeChangedEventArgs e
)

JScript unterstützt die Verwendung von Delegaten, aber nicht die Deklaration von neuen Delegaten.

Parameter

sender
Die Quelle des Ereignisses.

e
Ein XmlNodeChangedEventArgs, das die Ereignisdaten enthält.

Hinweise

Beim Erstellen eines XmlNodeChangedEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung. Um das Ereignis dem Ereignishandler zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird. Weitere Informationen über Ereignishandlerdelegaten finden Sie unter Ereignisse und Delegaten.

Beispiel

Das folgende Beispiel veranschaulicht die Behandlung des NodeChanged-Ereignisses und des NodeInserted-Ereignisses.

Imports System
Imports System.IO
Imports System.Xml

Namespace Microsoft.Samples.Xml

    Public Class Sample

        Private Const filename As String = "book.xml"

        Public Shared Sub Main()

            Dim mySample As Sample = New Sample()
            mySample.Run(filename)
        End Sub

        Public Sub Run(ByVal args As String)

            ' Create and load the XML document.
            Console.WriteLine("Loading file {0} ...", args)
            Dim doc As XmlDocument = New XmlDocument()
            doc.Load(args)

            'Create the event handlers.
            AddHandler doc.NodeChanged, AddressOf MyNodeChangedEvent
            AddHandler doc.NodeInserted, AddressOf MyNodeInsertedEvent

            ' Change the book price.
            doc.DocumentElement.LastChild.InnerText = "5.95"

            ' Add a new element.
            Dim newElem As XmlElement = doc.CreateElement("style")
            newElem.InnerText = "hardcover"
            doc.DocumentElement.AppendChild(newElem)

            Console.WriteLine()
            Console.WriteLine("Display the modified XML...")
            Console.WriteLine(doc.OuterXml)

        End Sub

        ' Handle the NodeChanged event.
        Private Sub MyNodeChangedEvent(ByVal source As Object, ByVal args As XmlNodeChangedEventArgs)
            Console.Write("Node Changed Event: <{0}> changed", args.Node.Name)
            If Not (args.Node.Value Is Nothing) Then
                Console.WriteLine(" with value  {0}", args.Node.Value)
            Else
                Console.WriteLine("")
            End If
        End Sub

        ' Handle the NodeInserted event.
        Private Sub MyNodeInsertedEvent(ByVal source As Object, ByVal args As XmlNodeChangedEventArgs)
            Console.Write("Node Inserted Event: <{0}> inserted", args.Node.Name)
            If Not (args.Node.Value Is Nothing) Then
                Console.WriteLine(" with value {0}", args.Node.Value)
            Else
                Console.WriteLine("")
            End If
        End Sub

    End Class

End Namespace

using System;
using System.IO;
using System.Xml;

namespace Microsoft.Samples.Xml
{
    public class Sample
    {
        private const String filename = "book.xml";

        public static void Main()
        {
            Sample mySample = new Sample();
            mySample.Run(filename);
        }

        public void Run(String args)
        {

            // Create and load the XML document.
            Console.WriteLine("Loading file {0} ...", args);
            XmlDocument doc = new XmlDocument();
            doc.Load(args);

            //Create the event handlers.
            doc.NodeChanged += new XmlNodeChangedEventHandler(this.MyNodeChangedEvent);
            doc.NodeInserted += new XmlNodeChangedEventHandler(this.MyNodeInsertedEvent);

            // Change the book price.
            doc.DocumentElement.LastChild.InnerText = "5.95";

            // Add a new element.
            XmlElement newElem = doc.CreateElement("style");
            newElem.InnerText = "hardcover";
            doc.DocumentElement.AppendChild(newElem);

            Console.WriteLine("\r\nDisplay the modified XML...");
            Console.WriteLine(doc.OuterXml);

        }

        // Handle the NodeChanged event.
        private void MyNodeChangedEvent(Object source, XmlNodeChangedEventArgs args)
        {
            Console.Write("Node Changed Event: <{0}> changed", args.Node.Name);
            if (args.Node.Value != null)
            {
                Console.WriteLine(" with value  {0}", args.Node.Value);
            }
            else
                Console.WriteLine("");
        }

        // Handle the NodeInserted event.
        private void MyNodeInsertedEvent(Object source, XmlNodeChangedEventArgs args)
        {
            Console.Write("Node Inserted Event: <{0}> inserted", args.Node.Name);
            if (args.Node.Value != null)
            {
                Console.WriteLine(" with value {0}", args.Node.Value);
            }
            else
                Console.WriteLine("");
        }

    } // End class

#using <System.Xml.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
public ref class Sample
{
public:
   void Run( String^ args )
   {
      // Create and load the XML document.
      Console::WriteLine( "Loading file {0} ...", args );
      XmlDocument^ doc = gcnew XmlDocument;
      doc->Load( args );
      
      //Create the event handlers.
      doc->NodeChanged += gcnew XmlNodeChangedEventHandler( this, &Sample::MyNodeChangedEvent );
      doc->NodeInserted += gcnew XmlNodeChangedEventHandler( this, &Sample::MyNodeInsertedEvent );
      
      // Change the book price.
      doc->DocumentElement->LastChild->InnerText = "5.95";
      
      // Add a new element.
      XmlElement^ newElem = doc->CreateElement( "style" );
      newElem->InnerText = "hardcover";
      doc->DocumentElement->AppendChild( newElem );
      Console::WriteLine( "\r\nDisplay the modified XML..." );
      Console::WriteLine( doc->OuterXml );
   }

   // Handle the NodeChanged event.
private:
   void MyNodeChangedEvent( Object^ /*src*/, XmlNodeChangedEventArgs^ args )
   {
      Console::Write( "Node Changed Event: <{0}> changed", args->Node->Name );
      if ( args->Node->Value != nullptr )
      {
         Console::WriteLine( " with value  {0}", args->Node->Value );
      }
      else
            Console::WriteLine( "" );
   }

   // Handle the NodeInserted event.
   void MyNodeInsertedEvent( Object^ /*src*/, XmlNodeChangedEventArgs^ args )
   {
      Console::Write( "Node Inserted Event: <{0}> inserted", args->Node->Name );
      if ( args->Node->Value != nullptr )
      {
         Console::WriteLine( " with value {0}", args->Node->Value );
      }
      else
            Console::WriteLine( "" );
   }
};
// End class 

int main()
{
   Sample^ mySample = gcnew Sample;
   mySample->Run( "book.xml" );
}

import System.*;
import System.IO.*;
import System.Xml.*;

public class Sample
{
    private static String filename = "book.xml";

    public static void main(String[] args)
    {
        Sample mySample = new Sample();
        mySample.Run(filename);
    } //main

    public void Run(String args)
    {
        // Create and load the XML document.
        Console.WriteLine("Loading file {0} ...", args);
        XmlDocument doc = new XmlDocument();
        doc.Load(args);
        //Create the event handlers.
        doc.add_NodeChanged(new XmlNodeChangedEventHandler(this.
            MyNodeChangedEvent));
        doc.add_NodeInserted(new XmlNodeChangedEventHandler(this.
            MyNodeInsertedEvent));
        // Change the book price.
        doc.get_DocumentElement().get_LastChild().set_InnerText("5.95");
        // Add a new element.
        XmlElement newElem = doc.CreateElement("style");
        newElem.set_InnerText("hardcover");
        doc.get_DocumentElement().AppendChild(newElem);

        Console.WriteLine("\r\nDisplay the modified XML...");
        Console.WriteLine(doc.get_OuterXml());
    } //Run

    // Handle the NodeChanged event.
    public void MyNodeChangedEvent(Object src, XmlNodeChangedEventArgs args)
    {
        Console.Write("Node Changed Event: <{0}> changed", args.get_Node().
            get_Name());
        if (args.get_Node().get_Value() != null) {
            Console.WriteLine(" with value  {0}", args.get_Node().
                get_Value());
        }
        else {
            Console.WriteLine("");
        }
    } //MyNodeChangedEvent

    // Handle the NodeInserted event.
    public void MyNodeInsertedEvent(Object src, XmlNodeChangedEventArgs args)
    {
        Console.Write("Node Inserted Event: <{0}> inserted", args.get_Node().
            get_Name());
        if (args.get_Node().get_Value() != null) {
            Console.WriteLine(" with value {0}", args.get_Node().get_Value());
        }
        else {
            Console.WriteLine("");
        }
    } //MyNodeInsertedEvent 
} //Sample

Im Beispiel wird die Datei book.xml als Eingabe verwendet.

<!--sample XML fragment-->
<book genre='novel' ISBN='1-861003-78' misc='sale-item'>
  <title>The Handmaid's Tale</title>
  <price>14.95</price>
</book>

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.

Freigeben über

XmlNodeChangedEventHandler-Delegat

Syntax

Parameter

Hinweise

Beispiel

Plattformen

Versionsinformationen

.NET Framework

.NET Compact Framework

Siehe auch

Referenz

Zusätzliche Ressourcen