XmlNodeChangedEventHandler Delegate
Assembly: System.Xml (in system.xml.dll)
'Declaration Public Delegate Sub XmlNodeChangedEventHandler ( _ sender As Object, _ e As XmlNodeChangedEventArgs _ ) 'Usage Dim instance As New XmlNodeChangedEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void XmlNodeChangedEventHandler ( Object sender, XmlNodeChangedEventArgs e )
JScript supports the use of delegates, but not the declaration of new ones.
Parameters
- sender
The source of the event.
- e
An XmlNodeChangedEventArgs containing the event data.
When you create an XmlNodeChangedEventHandler delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.
The following example shows how to handle the NodeChanged and NodeInserted events.
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
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
The example uses the file book.xml as input.
<!--sample XML fragment--> <book genre='novel' ISBN='1-861003-78' misc='sale-item'> <title>The Handmaid's Tale</title> <price>14.95</price> </book>
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.