PageAsyncTask.TimeoutHandler Eigenschaft

  • Referenz

Definition

Namespace:
System.Web.UI
Assembly:
System.Web.dll

Ruft die Methode ab, die aufgerufen werden soll, wenn die Aufgabe innerhalb des Timeoutzeitraums nicht erfolgreich abgeschlossen wird.

public:
 property System::Web::EndEventHandler ^ TimeoutHandler { System::Web::EndEventHandler ^ get(); };
public System.Web.EndEventHandler TimeoutHandler { get; }
member this.TimeoutHandler : System.Web.EndEventHandler
Public ReadOnly Property TimeoutHandler As EndEventHandler

Eigenschaftswert

EndEventHandler

Ein EndEventHandler-Delegat, der die Methode darstellt, die aufgerufen werden soll, wenn die Aufgabe innerhalb des Timeoutzeitraums nicht erfolgreich abgeschlossen wird.

Beispiele

Im folgenden Codebeispiel werden drei asynchrone Aufgaben auf einer Seite registriert und parallel ausgeführt. Jede Aufgabe ruft eine Methode auf, die lediglich bewirkt, dass der Thread 5 Sekunden lang in den Standbymodus versetzt wird. Für jede Aufgabe wird ein TimeoutHandler Delegat angegeben.

<%@ Page Language="C#" Async="true" AsyncTimeout="35"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    
  protected void Page_Load(object sender, EventArgs e)
  {
      
    // Define the asynchronuous task.
    Samples.AspNet.CS.Controls.SlowTask slowTask1 =    
      new Samples.AspNet.CS.Controls.SlowTask();
    Samples.AspNet.CS.Controls.SlowTask slowTask2 =
    new Samples.AspNet.CS.Controls.SlowTask();
    Samples.AspNet.CS.Controls.SlowTask slowTask3 =
    new Samples.AspNet.CS.Controls.SlowTask();
    
    // <Snippet3> 
    PageAsyncTask asyncTask1 = new PageAsyncTask(slowTask1.OnBegin, slowTask1.OnEnd, slowTask1.OnTimeout, "Async1", true);
    PageAsyncTask asyncTask2 = new PageAsyncTask(slowTask2.OnBegin, slowTask2.OnEnd, slowTask2.OnTimeout, "Async2", true);
    PageAsyncTask asyncTask3 = new PageAsyncTask(slowTask3.OnBegin, slowTask3.OnEnd, slowTask3.OnTimeout, "Async3", true);

    // Register the asynchronous task.
    Page.RegisterAsyncTask(asyncTask1);
    Page.RegisterAsyncTask(asyncTask2);
    Page.RegisterAsyncTask(asyncTask3);
    // </Snippet3>
      
    // Execute the register asynchronous task.
    Page.ExecuteRegisteredAsyncTasks();

    TaskMessage.InnerHtml = slowTask1.GetAsyncTaskProgress()+ "<br />" + slowTask2.GetAsyncTaskProgress() + "<br />" + slowTask3.GetAsyncTaskProgress();

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Asynchronous Task Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <span id="TaskMessage" runat="server">
      </span>
    </div>
    </form>
</body>
</html>

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
      
        ' Define the asynchronuous task.
        Dim slowTask1 As New Samples.AspNet.VB.Controls.SlowTask()
        Dim slowTask2 As New Samples.AspNet.VB.Controls.SlowTask()
        Dim slowTask3 As New Samples.AspNet.VB.Controls.SlowTask()
     
        ' <Snippet3>
        Dim asyncTask1 As New PageAsyncTask(AddressOf slowTask1.OnBegin, AddressOf slowTask1.OnEnd, AddressOf slowTask1.OnTimeout, "Async1", True)
        Dim asyncTask2 As New PageAsyncTask(AddressOf slowTask2.OnBegin, AddressOf slowTask2.OnEnd, AddressOf slowTask2.OnTimeout, "Async2", True)
        Dim asyncTask3 As New PageAsyncTask(AddressOf slowTask3.OnBegin, AddressOf slowTask3.OnEnd, AddressOf slowTask3.OnTimeout, "Async3", True)

        ' Register the asynchronous task.
        Page.RegisterAsyncTask(asyncTask1)
        Page.RegisterAsyncTask(asyncTask2)
        Page.RegisterAsyncTask(asyncTask3)
        ' </Snippet3>
      
        ' Execute the register asynchronous task.
        Page.ExecuteRegisteredAsyncTasks()

        TaskMessage.InnerHtml = slowTask1.GetAsyncTaskProgress() + "<br />" + slowTask2.GetAsyncTaskProgress() + "<br />" + slowTask3.GetAsyncTaskProgress()

    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <span id="TaskMessage" runat="server">
      </span>
    </div>
    </form>
</body>
</html>

using System;
using System.Web;
using System.Web.UI;
using System.Threading;

namespace Samples.AspNet.CS.Controls
{
    public class SlowTask
    {
        private String _taskprogress;
        private AsyncTaskDelegate _dlgt;

        // Create delegate.
        protected delegate void AsyncTaskDelegate();

        public String GetAsyncTaskProgress()
        {
            return _taskprogress;
        }
        public void ExecuteAsyncTask()
        {
            // Introduce an artificial delay to simulate a delayed 
            // asynchronous task.
            Thread.Sleep(TimeSpan.FromSeconds(5.0));
        }

        // Define the method that will get called to
        // start the asynchronous task.
        public IAsyncResult OnBegin(object sender, EventArgs e,
            AsyncCallback cb, object extraData)
        {
            _taskprogress = "AsyncTask started at: " + DateTime.Now + ". ";

            _dlgt = new AsyncTaskDelegate(ExecuteAsyncTask);
            IAsyncResult result = _dlgt.BeginInvoke(cb, extraData);

            return result;
        }

        // Define the method that will get called when
        // the asynchronous task is ended.
        public void OnEnd(IAsyncResult ar)
        {
            _taskprogress += "AsyncTask completed at: " + DateTime.Now;
            _dlgt.EndInvoke(ar);
        }

        // Define the method that will get called if the task
        // is not completed within the asynchronous timeout interval.
        public void OnTimeout(IAsyncResult ar)
        {
            _taskprogress += "AsyncTask failed to complete " +
                "because it exceeded the AsyncTimeout parameter.";
        }
    }
}

Imports System.Threading

Namespace Samples.AspNet.VB.Controls

    Public Class SlowTask
        Private _taskprogress As String
        Private _dlgt As AsyncTaskDelegate

        ' Create delegate.
        Protected Delegate Sub AsyncTaskDelegate()

        Public Function GetAsyncTaskProgress() As String
            Return _taskprogress
        End Function

        Public Sub ExecuteAsyncTask()
            ' Introduce an artificial delay to simulate a delayed 
            ' asynchronous task.
            Thread.Sleep(TimeSpan.FromSeconds(5.0))
        End Sub

        ' Define the method that will get called to
        ' start the asynchronous task.
        Public Function OnBegin(ByVal sender As Object, ByVal e As EventArgs, ByVal cb As AsyncCallback, ByVal extraData As Object) As IAsyncResult
            _taskprogress = "AsyncTask started at: " + DateTime.Now.ToString + ". "

            _dlgt = New AsyncTaskDelegate(AddressOf ExecuteAsyncTask)
            Dim result As IAsyncResult = _dlgt.BeginInvoke(cb, extraData)

            Return result
        End Function

        ' Define the method that will get called when
        ' the asynchronous task is ended.
        Public Sub OnEnd(ByVal ar As IAsyncResult)
            _taskprogress += "AsyncTask completed at: " + DateTime.Now.ToString
            _dlgt.EndInvoke(ar)
        End Sub


        ' Define the method that will get called if the task
        ' is not completed within the asynchronous timeout interval.
        Public Sub OnTimeout(ByVal ar As IAsyncResult)
            _taskprogress += "AsyncTask failed to complete " + _
                "because it exceeded the AsyncTimeout parameter."
        End Sub
    End Class
End Namespace

Hinweise

Der TimeoutHandler Delegat wird im Konstruktor festgelegt.

Gilt für: