PageAsyncTask.EndHandler プロパティとは何？わかりやすく解説 Weblio辞書

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PageAsyncTask.EndHandler プロパティ

メモ : このプロパティは、.NET Framework version 2.0 で新しく追加されたものです。

タイムアウト期限内にタスクが正常に完了したときに呼び出すメソッドを取得します。

名前空間: System.Web.UI
アセンブリ: System.Web (system.web.dll 内)
構文

Visual Basic (宣言)

Public ReadOnly Property
 EndHandler As EndEventHandler

Visual Basic (使用法)

Dim instance As PageAsyncTask
Dim value As EndEventHandler

value = instance.EndHandler

public EndEventHandler EndHandler { get; }

C++

public:
property EndEventHandler^ EndHandler {
    EndEventHandler^ get ();
}

/** @property */
public EndEventHandler get_EndHandler ()

JScript

public function get EndHandler
 () : EndEventHandler

プロパティ値
タイムアウト期限内にタスクが正常に完了したときに呼び出すメソッドを表す EndEventHandler デリゲート。

解説

EndHandler デリゲートは、コンストラクタで設定されます。

使用例

3 つの非同期タスクをページに登録し、並列で処理する方法を次のコード例に示します。各タスクは、単にスレッドを 5 秒間スリープ状態にするメソッドを呼び出します。各タスクに対して EndHandler デリゲートが指定されています。

Visual Basic

<%@ 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()
     
        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)
      
        ' Execute the register asynchronous task.
        Page.ExecuteRegisteredAsyncTasks()

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

    End Sub
</script>

<html  >
<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>

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

<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();
    
    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);
      
    // Execute the register asynchronous task.
    Page.ExecuteRegisteredAsyncTasks();

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

  }
</script>

<html  >
<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>

Visual Basic

Imports Microsoft.VisualBasic
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

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.";
        }
    }
}