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MessageQueue.EndReceive Method

Completes the specified asynchronous receive operation.

Namespace: System.Messaging
Assembly: System.Messaging (in system.messaging.dll)

public Message EndReceive (
	IAsyncResult asyncResult
)
public Message EndReceive (
	IAsyncResult asyncResult
)
public function EndReceive (
	asyncResult : IAsyncResult
) : Message

Parameters

asyncResult

The IAsyncResult that identifies the asynchronous receive operation to finish and from which to retrieve an end result.

Return Value

The Message associated with the completed asynchronous operation.

Exception typeCondition

ArgumentNullException

The asyncResult parameter is a null reference (Nothing in Visual Basic).

ArgumentException

The syntax of the asyncResult parameter is not valid.

MessageQueueException

An error occurred when accessing a Message Queuing method.

When the ReceiveCompleted event is raised, EndReceive completes the operation that was initiated by the BeginReceive call. To do so, EndReceive receives the message.

BeginReceive can specify a time-out, which causes the ReceiveCompleted event to be raised if the time-out occurs before a message appears in the queue. In this case, the IsCompleted property of the asyncResult parameter is set to true, but no message is associated with the operation. When a time-out occurs without a message arriving in the queue, a subsequent call to EndReceive throws an exception.

EndReceive is used to read (removing from the queue) the message that caused the ReceiveCompleted event to be raised.

If you want to continue to asynchronously receive messages, you can again call BeginReceive after calling EndReceive.

The following table shows whether this method is available in various Workgroup modes.

Workgroup mode

Available

Local computer

Yes

Local computer and direct format name

Yes

Remote computer

No

Remote computer and direct format name

Yes

The following code example chains asynchronous requests. It assumes there is a queue on the local computer called "myQueue". The Main function begins the asynchronous operation that is handled by the MyReceiveCompleted routine. MyReceiveCompleted processes the current message and begins a new asynchronous receive operation.

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; 
		}
	}
}

package MyProject;
import System.*;
import System.Messaging.*;
import System.Threading.*;

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

    //**************************************************
    // Provides an entry point into the application.
    //         
    // This example performs asynchronous receive
    // operation processing.
    //**************************************************
    public static void main(String[] args)
    {
        // Create an instance of MessageQueue. Set its formatter.
        MessageQueue myQueue = new MessageQueue(".\\myQueue");
        myQueue.set_Formatter(new XmlMessageFormatter(new Type[] 
            { String.class.ToType() }));

        // Add an event handler for the ReceiveCompleted event.
        myQueue.add_ReceiveCompleted(new ReceiveCompletedEventHandler(
            MyReceiveCompleted));

        // Begin the asynchronous receive operation.
        myQueue.BeginReceive();
        signal.WaitOne();

        // Do other work on the current thread.

        return;
    } //main

    //***************************************************
    // 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.get_AsyncResult());

            count += 1;
            if (count == 10) {
                signal.Set();
            }

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

        // Handle other exceptions.

        return;
    } //MyReceiveCompleted
} //MyNewQueue

  • Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see .

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0

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