共用方式為


MessageQueue.EndReceive(IAsyncResult) 方法

定義

完成指定的非同步接收作業。

public:
 System::Messaging::Message ^ EndReceive(IAsyncResult ^ asyncResult);
public System.Messaging.Message EndReceive (IAsyncResult asyncResult);
member this.EndReceive : IAsyncResult -> System.Messaging.Message
Public Function EndReceive (asyncResult As IAsyncResult) As Message

參數

asyncResult
IAsyncResult

IAsyncResult,識別要完成的非同步接收作業,並要從其中擷取最終結果。

傳回

與完成的非同步作業相關的 Message

例外狀況

asyncResult 參數為 null

asyncResult 參數的語法無效。

存取訊息佇列方法時發生錯誤。

範例

下列程式代碼範例會鏈結異步要求。 它假設本機電腦上有一個名為 「myQueue」 的佇列。 函 Main 式會開始由例程處理的 MyReceiveCompleted 異步操作。 MyReceiveCompleted 會處理目前的訊息,並開始新的異步接收作業。

#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;
using namespace System::Threading;

ref class MyNewQueue
{
public:

   // Define static class members.
   static ManualResetEvent^ signal = gcnew ManualResetEvent( false );
   static int count = 0;

   // Provides an event handler for the ReceiveCompleted
   // event.
   static void MyReceiveCompleted( Object^ source, ReceiveCompletedEventArgs^ asyncResult )
   {
      try
      {
         // Connect to the queue.
         MessageQueue^ mq = dynamic_cast<MessageQueue^>(source);

         // End the asynchronous receive operation.
         mq->EndReceive( asyncResult->AsyncResult );
         count += 1;
         if ( count == 10 )
         {
            signal->Set();
         }

         // Restart the asynchronous receive operation.
         mq->BeginReceive();
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle sources of MessageQueueException.
      }

      // Handle other exceptions.
      return;
   }
};

// Provides an entry point into the application.
//         
// This example performs asynchronous receive
// operation processing.
int main()
{
   // Create an instance of MessageQueue. Set its formatter.
   MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );
   array<Type^>^p = gcnew array<Type^>(1);
   p[ 0 ] = String::typeid;
   myQueue->Formatter = gcnew XmlMessageFormatter( p );

   // Add an event handler for the ReceiveCompleted event.
   myQueue->ReceiveCompleted += gcnew ReceiveCompletedEventHandler( MyNewQueue::MyReceiveCompleted );

   // Begin the asynchronous receive operation.
   myQueue->BeginReceive();
   MyNewQueue::signal->WaitOne();

   // Do other work on the current thread.
   return 0;
}
using System;
using System.Messaging;
using System.Threading;

namespace MyProject
{
    /// <summary>
    /// Provides a container class for the example.
    /// </summary>
    public class MyNewQueue
    {
        // Define static class members.
        static ManualResetEvent signal = new ManualResetEvent(false);
        static int count = 0;

        //**************************************************
        // Provides an entry point into the application.
        //		
        // This example performs asynchronous receive
        // operation processing.
        //**************************************************

        public static void Main()
        {
            // Create an instance of MessageQueue. Set its formatter.
            MessageQueue myQueue = new MessageQueue(".\\myQueue");
            myQueue.Formatter = new XmlMessageFormatter(new Type[]
                {typeof(String)});

            // Add an event handler for the ReceiveCompleted event.
            myQueue.ReceiveCompleted +=
                new ReceiveCompletedEventHandler(MyReceiveCompleted);
            
            // Begin the asynchronous receive operation.
            myQueue.BeginReceive();

            signal.WaitOne();
            
            // Do other work on the current thread.

            return;
        }

        //***************************************************
        // Provides an event handler for the ReceiveCompleted
        // event.
        //***************************************************
        
        private static void MyReceiveCompleted(Object source,
            ReceiveCompletedEventArgs asyncResult)
        {
            try
            {
                // Connect to the queue.
                MessageQueue mq = (MessageQueue)source;

                // End the asynchronous receive operation.
                Message m = mq.EndReceive(asyncResult.AsyncResult);
                
                count += 1;
                if (count == 10)
                {
                    signal.Set();
                }

                // Restart the asynchronous receive operation.
                mq.BeginReceive();
            }
            catch(MessageQueueException)
            {
                // Handle sources of MessageQueueException.
            }
            
            // Handle other exceptions.
            
            return;
        }
    }
}
Imports System.Messaging
Imports System.Threading




' Provides a container class for the example.

Public Class MyNewQueue

        ' Define static class members.
        Private Shared signal As New ManualResetEvent(False)
        Private Shared count As Integer = 0



        ' Provides an entry point into the application.
        '		 
        ' This example performs asynchronous receive
        ' operation processing.


        Public Shared Sub Main()
            ' Create an instance of MessageQueue. Set its formatter.
            Dim myQueue As New MessageQueue(".\myQueue")
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType([String])})

            ' Add an event handler for the ReceiveCompleted event.
            AddHandler myQueue.ReceiveCompleted, AddressOf _
                MyReceiveCompleted

            ' Begin the asynchronous receive operation.
            myQueue.BeginReceive()

            signal.WaitOne()

            ' Do other work on the current thread.

            Return

        End Sub



        ' Provides an event handler for the ReceiveCompleted
        ' event.


        Private Shared Sub MyReceiveCompleted(ByVal [source] As _
            [Object], ByVal asyncResult As ReceiveCompletedEventArgs)

            Try
                ' Connect to the queue.
                Dim mq As MessageQueue = CType([source], MessageQueue)

                ' End the asynchronous receive operation.
                Dim m As Message = _
                    mq.EndReceive(asyncResult.AsyncResult)

                count += 1
                If count = 10 Then
                    signal.Set()
                End If

                ' Restart the asynchronous receive operation.
                mq.BeginReceive()

            Catch
                ' Handle sources of MessageQueueException.

                ' Handle other exceptions.

            End Try

            Return

        End Sub

End Class

備註

ReceiveCompleted引發事件時,EndReceive(IAsyncResult)完成呼叫所起始的BeginReceive作業。 若要這樣做, EndReceive(IAsyncResult) 請接收訊息。

BeginReceive 可以指定逾時,這會導致 ReceiveCompleted 在訊息出現在佇列中的訊息之前引發事件。 當逾時發生時,沒有訊息抵達佇列時,後續呼叫 會 EndReceive(IAsyncResult) 擲回例外狀況。

EndReceive(IAsyncResult) 用來讀取 (從佇列中移除) 導致 ReceiveCompleted 引發事件的訊息。

如果您要繼續以異步方式接收訊息,您可以在呼叫 之後再次呼叫 BeginReceiveEndReceive(IAsyncResult)

下表顯示這個方法是否可在各種工作組模式中使用。

工作組模式 可用
本機電腦
本機計算機和直接格式名稱
遠端電腦
遠端電腦和直接格式名稱

適用於

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