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ReceiveCompletedEventArgs Class

Provides data for the ReceiveCompleted event. When your asynchronous receive operation calls an event handler, an instance of this class is passed to the handler.

For a list of all members of this type, see ReceiveCompletedEventArgs Members.

System.Object
   System.EventArgs
      System.Messaging.ReceiveCompletedEventArgs

[Visual Basic]
Public Class ReceiveCompletedEventArgs
   Inherits EventArgs
[C#]
public class ReceiveCompletedEventArgs : EventArgs
[C++]
public __gc class ReceiveCompletedEventArgs : public EventArgs
[JScript]
public class ReceiveCompletedEventArgs extends EventArgs

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

When you use event notification to receive messages asynchronously from the queue, you must create a method that handles your message processing. Your code must call BeginReceive to begin the asynchronous processing. When a message is received, your application is notified through the ReceiveCompleted event. An instance of ReceiveCompletedEventArgs is passed into the event delegate that calls your event handler. The data associated with the ReceiveCompleted event is contained in the delegate's AsyncResult parameter.

Note   There are two ways to provide notification of event completion: event notification and callbacks. ReceiveCompletedEventArgs is used only with event notification. For information comparing callbacks and event notification, see "Events vs. Callbacks" on MSDN.

ReceiveCompletedEventArgs provides access to the message that initiated the end of the asynchronous receive operation, through the Message member. This is an alternate access to the message, and behaves much the same as a call to MessageQueue.EndReceive.

Example

[Visual Basic, C#, C++] The following example creates an event handler for the ReceiveCompleted event and associates it with the event delegate by using the ReceiveCompletedEventHandler. The event handler, MyReceiveCompleted, receives a message from a queue and writes its body to the screen.

[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

Namespace: System.Messaging

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

Assembly: System.Messaging (in System.Messaging.dll)

See Also

ReceiveCompletedEventArgs Members | System.Messaging Namespace | MessageQueue | ReceiveCompletedEventHandler | ReceiveCompleted | BeginReceive | EndReceive | Message

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