ReceiveCompleted Event
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MessageQueue.ReceiveCompleted Event

Occurs when a message has been removed from the queue. This event is raised by the asynchronous operation, BeginReceive.

[Visual Basic]
Public Event ReceiveCompleted As ReceiveCompletedEventHandler
[C#]
public event ReceiveCompletedEventHandler ReceiveCompleted;
[C++]
public: __event ReceiveCompletedEventHandler* ReceiveCompleted;

[JScript] In JScript, you can handle the events defined by a class, but you cannot define your own.

Event Data

The event handler receives an argument of type ReceiveCompletedEventArgs containing data related to this event. The following ReceiveCompletedEventArgs properties provide information specific to this event.

Property Description
AsyncResult Gets or sets the result of the asynchronous operation requested.
Message Gets the message associated with the asynchronous receive operation.

Remarks

BeginReceive is used in asynchronous processing to raise the ReceiveCompleted event when a message is available in the queue.

EndReceive is used to complete the operation initiated by a call to BeginReceive and peek the message when the ReceiveCompleted event is raised.

When you create a ReceiveCompletedEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.

Example

[Visual Basic, C#, C++] The following example creates an event handler named MyReceiveCompleted, attaches it to the ReceiveCompleted event handler delegate, and calls BeginReceive to initiate an asynchronous receive operation on the queue that is located at the path ".\myQueue". When a ReceiveCompleted event is raised, the example receives the message and writes its body to the screen. The example then calls BeginReceive again to initiate a new asynchronous receive operation.

[Visual Basic] 
Imports System
Imports System.Messaging

Namespace MyProject

    '/ <summary>
    '/ Provides a container class for the example.
    '/ </summary>
    Public Class MyNewQueue


        '**************************************************
        ' 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()

            ' Do other work on the current thread.

            Return

        End Sub 'Main


        '**************************************************
        ' Provides an event handler for the ReceiveCompleted
        ' event.
        '**************************************************

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

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

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

            ' Display message information on the screen.
            Console.WriteLine(("Message: " + CStr(m.Body)))

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

            Return

        End Sub 'MyReceiveCompleted

    End Class 'MyNewQueue
End Namespace 'MyProject

[C#] 
using System;
using System.Messaging;

namespace MyProject
{
    /// <summary>
    /// Provides a container class for the example.
    /// </summary>
    public class MyNewQueue
    {

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

            return;
        }


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

            // End the asynchronous Receive operation.
            Message m = mq.EndReceive(asyncResult.AsyncResult);

            // Display message information on the screen.
            Console.WriteLine("Message: " + (string)m.Body);

            // Restart the asynchronous Receive operation.
            mq.BeginReceive();
            
            return; 
        }
    }
}

[C++] 
#using <mscorlib.dll>
#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;

__gc class MyNewQueue 
{
    //*************************************************
    // Provides an event handler for the ReceiveCompleted
    // event.
    //*************************************************
public:
    static void MyReceiveCompleted(Object* source, 
        ReceiveCompletedEventArgs* asyncResult) 
    {
        // Connect to the queue.
        MessageQueue* mq = dynamic_cast<MessageQueue*>(source);

        // End the asynchronous Receive operation.
        Message* m = mq->EndReceive(asyncResult->AsyncResult);

        // Display message information on the screen.
        Console::WriteLine(S"Message: {0}", m->Body);

        // Restart the asynchronous Receive operation.
        mq->BeginReceive();

        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 = new MessageQueue(S".\\myQueue");

    Type* p __gc[] = new Type* __gc[1];
    p[0] = __typeof(String);
    myQueue->Formatter = new XmlMessageFormatter( p );

    // Add an event handler for the ReceiveCompleted event.
    myQueue->ReceiveCompleted += new ReceiveCompletedEventHandler(0, MyNewQueue::MyReceiveCompleted);

    // Begin the asynchronous receive operation.
    myQueue->BeginReceive();

    // Do other work on the current thread.
    return 0;
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

MessageQueue Class | MessageQueue Members | System.Messaging Namespace | BeginReceive | EndReceive | PeekCompleted | TimeSpan | AsyncCallback | IAsyncResult

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