ReceiveCompletedEventArgs Class
Assembly: System.Messaging (in system.messaging.dll)
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.
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.
The following code 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.
Imports System Imports System.Messaging 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
package MyProject;
import System.*;
import System.Messaging.*;
/// <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(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();
// 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)
{
// Connect to the queue.
MessageQueue mq = (MessageQueue)source;
// End the asynchronous Receive operation.
Message m = mq.EndReceive(asyncResult.get_AsyncResult());
// Display message information on the screen.
Console.WriteLine("Message: " + (String)(m.get_Body()));
// Restart the asynchronous Receive operation.
mq.BeginReceive();
return;
} //MyReceiveCompleted
} //MyNewQueue
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.