Page.ExecuteRegisteredAsyncTasks Page.ExecuteRegisteredAsyncTasks Page.ExecuteRegisteredAsyncTasks Page.ExecuteRegisteredAsyncTasks Method

定義

非同期操作の実行を開始します。Starts the execution of an asynchronous task.

public:
 void ExecuteRegisteredAsyncTasks();
public void ExecuteRegisteredAsyncTasks ();
member this.ExecuteRegisteredAsyncTasks : unit -> unit
Public Sub ExecuteRegisteredAsyncTasks ()

例外

非同期操作での例外です。There is an exception in the asynchronous task.

次のコード例では、メソッドAsyncTimeout ExecuteRegisteredAsyncTasksRegisterAsyncTaskメソッドを使用してプロパティを使用する方法を示します。The following code example demonstrates the use of the AsyncTimeout property with the ExecuteRegisteredAsyncTasks and RegisterAsyncTask methods. 開始、終了、およびタイムアウトハンドラーの使用に注意してください。Note the use of beginning, ending, and time-out handlers. この例では、 AsyncTimeoutプロパティで指定されているタスクに割り当てられた時間を超える非同期タスクの状況を示すために、人為的な遅延が発生します。In the example, an artificial delay is introduced to demonstrate the situation of an asynchronous task exceeding the allotted time for the task as specified in the AsyncTimeout property. 実際のシナリオでは、非同期タスクを使用してデータベース呼び出しやイメージの生成を実行できます。また、タイムアウトハンドラーは、タスクが指定された時間内に実行されない場合に、正常なパフォーマンス低下を提供します。In a real-world scenario, an asynchronous task could be used to perform database calls or image generation, for example, and the time-out handler provides graceful degradation if the task is not performed in a specified amount of time.

<%@ Page Language="C#" AsyncTimeout="2"%>

<!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.MyAsyncTask mytask =    
      new Samples.AspNet.CS.Controls.MyAsyncTask();
    PageAsyncTask asynctask = new PageAsyncTask(mytask.OnBegin, mytask.OnEnd, mytask.OnTimeout, null);

    // Register the asynchronous task.
    Page.RegisterAsyncTask(asynctask);
      
    // Execute the register asynchronous task.
    Page.ExecuteRegisteredAsyncTasks();

    TaskMessage.InnerHtml = mytask.GetAsyncTaskProgress();

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head 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" AsyncTimeout="2"%>

<!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 System.EventArgs)
    
    ' Define the asynchronuous task.
    Dim mytask As New Samples.AspNet.VB.Controls.MyAsyncTask()
    Dim asynctask As New PageAsyncTask(AddressOf mytask.OnBegin, AddressOf mytask.OnEnd, AddressOf mytask.OnTimeout, DBNull.Value)

    ' Register the asynchronous task.
    Page.RegisterAsyncTask(asynctask)
      
    ' Execute the register asynchronous task.
    Page.ExecuteRegisteredAsyncTasks()

    TaskMessage.InnerHtml = mytask.GetAsyncTaskProgress()
    
  End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head 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>
using System;
using System.Web;
using System.Web.UI;
using System.Threading;

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

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

		public String GetAsyncTaskProgress()
		{
			return _taskprogress;
		}
		public void DoTheAsyncTask()
		{
			// Introduce an artificial delay to simulate a delayed 
			// asynchronous task. Make this greater than the 
			// AsyncTimeout property.
			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 = "Beginning async task.";

			_dlgt = new AsyncTaskDelegate(DoTheAsyncTask);
			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 = "Asynchronous task completed.";
			_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 = "Ansynchronous task failed to complete " +
				"because it exceeded the AsyncTimeout parameter.";
		}
	}
}
Imports System.Web
Imports System.Web.UI
Imports System.Threading

Namespace Samples.AspNet.VB.Controls

    Public Class MyAsyncTask

        Private _taskprogress As String
        Private _dlgt As AsyncTaskDelegate

        ' Create delegate.
        Delegate Function AsyncTaskDelegate()

        Public Function GetAsyncTaskProgress() As String
            Return _taskprogress
        End Function

        Public Function DoTheAsyncTask()

            ' Introduce an artificial delay to simulate a delayed 
            ' asynchronous task. Make this greater than the 
            ' AsyncTimeout property.
            Thread.Sleep(TimeSpan.FromSeconds(5.0))

        End Function


        ' 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 = "Beginning async task."

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

        End Function 'OnBegin

        ' Define the method that will get called when
        ' the asynchronous task is ended.
        Public Sub OnEnd(ByVal ar As IAsyncResult)

            _taskprogress = "Asynchronous task completed."
            _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 = "Ansynchronous task failed to complete because " & _
            "it exceeded the AsyncTimeout parameter."

        End Sub

    End Class

End Namespace

注釈

クラスを使用して、 PageAsyncTask非同期タスクを定義します。Define an asynchronous task using the PageAsyncTask class. タスクが定義され、 RegisterAsyncTaskメソッドを使用してページに登録されるとExecuteRegisteredAsyncTasks 、メソッドを呼び出して非同期タスクを開始できます。After the task is defined, and is registered with the page using the RegisterAsyncTask method, the ExecuteRegisteredAsyncTasks method can be invoked to begin the asynchronous task.

ExecuteRegisteredAsyncTasksメソッドは、登録されている非同期タスク (存在する場合) が非同期ページ以外で呼び出されると、ページ処理のポイントで自動的に呼び出されます。The ExecuteRegisteredAsyncTasks method is automatically called at the point in the page processing when any registered asynchronous tasks, if they exist, are invoked for a non-asynchronous page. この自動呼び出しExecuteRegisteredAsyncTasksは、イベントのPreRenderComplete直前に発生します。This automatic call to ExecuteRegisteredAsyncTasks occurs just before the PreRenderComplete event. このメソッドExecuteRegisteredAsyncTasksへの自動呼び出し以外の時間に呼び出されるタスクに対して、メソッドを呼び出します。Call the ExecuteRegisteredAsyncTasks method for tasks you want to be invoked at times other than the automatic call to this method. 非同期タスクは、複数回呼び出されるExecuteRegisteredAsyncTasksこともありますが、1回だけ実行されることに注意してください。Note, asynchronous tasks will be executed only once even though ExecuteRegisteredAsyncTasks may be called more than once.

プロパティは、 ExecuteRegisteredAsyncTasksメソッドを呼び出すたびにリセットされます。 AsyncTimeoutThe AsyncTimeout property is reset on every call to the ExecuteRegisteredAsyncTasks method. メソッドExecuteRegisteredAsyncTasksを呼び出すAsyncTimeout前のの最後の値が優先されます。The last value of the AsyncTimeout prior to invoking the ExecuteRegisteredAsyncTasks method takes precedence. 非同期タスクAsyncTimeoutがを超える場合、その呼び出し中に呼び出されるExecuteRegisteredAsyncTasks後続のタスクはすぐにタイムアウトになります。If an asynchronous task takes more than the AsyncTimeout, subsequent tasks invoked during that ExecuteRegisteredAsyncTasks call are timed out immediately.

適用対象

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