EndEventHandler Delegate

Definition

Represents the method that handles asynchronous events such as application events.

C#
public delegate void EndEventHandler(IAsyncResult ar);

Parameters

ar
IAsyncResult

The IAsyncResult that is the result of the BeginEventHandler operation.

Examples

The following code example uses the EndEventHandler delegate to register a handler for an asynchronous page.

ASP.NET (C#)
<%@ page language="C#" Async="true"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  System.Net.WebRequest myRequest;

  void Page_Load(object sender, EventArgs e)
  {
    Label1.Text = "Page_Load: thread #" + System.Threading.Thread.CurrentThread.GetHashCode();

    BeginEventHandler bh = new BeginEventHandler(this.BeginGetAsyncData);
    EndEventHandler eh = new EndEventHandler(this.EndGetAsyncData);

    AddOnPreRenderCompleteAsync(bh, eh);

    // Initialize the WebRequest.
    string address = "http://localhost/";

    myRequest = System.Net.WebRequest.Create(address);
  }

  IAsyncResult BeginGetAsyncData(Object src, EventArgs args, AsyncCallback cb, Object state)
  {
    Label2.Text = "BeginGetAsyncData: thread #" + System.Threading.Thread.CurrentThread.GetHashCode();
    return myRequest.BeginGetResponse(cb, state);
  }

  void EndGetAsyncData(IAsyncResult ar)
  {
    Label3.Text = "EndGetAsyncData: thread #" + System.Threading.Thread.CurrentThread.GetHashCode();

    System.Net.WebResponse myResponse = myRequest.EndGetResponse(ar);

    result.Text = new System.IO.StreamReader(myResponse.GetResponseStream()).ReadToEnd();
    myResponse.Close();
  }

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>
      Page.AddOnPreRenderCompleteAsync Example</title>
  </head>
  <body>
    <form id="form1" runat="server">
      <asp:label id="Label1" runat="server">
        Label 1</asp:label><br />
      <asp:label id="Label2" runat="server">
        Label 2</asp:label><br />
      <asp:label id="Label3" runat="server">
        Label 3</asp:label><br />
      <asp:textbox id="result" runat="server" textMode="multiLine" ReadOnly="true" columns="80" rows="25" />
    </form>
  </body>
</html>

Remarks

This delegate is called by the event source when completion of the asynchronous operation is signaled by a callback to the BeginEventHandler delegate.

When you create an EndEventHandler delegate, you identify the method that will handle 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 Handling and Raising Events.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.

Applies to

Product Versions
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also