XmlNodeChangedEventHandler Delegat

Definition

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

public delegate void XmlNodeChangedEventHandler(object sender, XmlNodeChangedEventArgs e);

type XmlNodeChangedEventHandler = delegate of obj * XmlNodeChangedEventArgs -> unit

Public Delegate Sub XmlNodeChangedEventHandler(sender As Object, e As XmlNodeChangedEventArgs)

Parameter

Beispiele

Im folgenden Beispiel wird gezeigt, wie die NodeChanged Ereignisse und NodeInserted behandelt werden.

#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" );
}

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

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

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>

Hinweise

Wenn Sie einen XmlNodeChangedEventHandler Delegaten erstellen, identifizieren Sie die Methode, die das Ereignis behandelt. Um dem Ereignishandler das Ereignis 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 zu Ereignishandlerdelegierten finden Sie unter Behandeln und Auslösen von Ereignissen.

Erweiterungsmethoden

Gilt für: