MessageQueue.ReceiveCompleted Event
Definition
Important
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Occurs when a message has been removed from the queue. This event is raised by the asynchronous operation, BeginReceive().
public:
event System::Messaging::ReceiveCompletedEventHandler ^ ReceiveCompleted;[System.Messaging.MessagingDescription("MQ_ReceiveCompleted")]
public event System.Messaging.ReceiveCompletedEventHandler ReceiveCompleted;[<System.Messaging.MessagingDescription("MQ_ReceiveCompleted")>]
member this.ReceiveCompleted : System.Messaging.ReceiveCompletedEventHandler Public Custom Event ReceiveCompleted As ReceiveCompletedEventHandler Event Type
- Attributes
Examples
The following code 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.
#using <system.dll>
#using <system.messaging.dll>
using namespace System;
using namespace System::Messaging;
ref class MyNewQueue
{
public:
//*************************************************
// Provides an event handler for the ReceiveCompleted
// event.
//*************************************************
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( "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 = 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();
// Do other work on the current thread.
return 0;
}
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;
}
}
}
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
'
' 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
End Class
Remarks
BeginReceive is used in asynchronous processing to raise the ReceiveCompleted event when a message is available in the queue.
EndReceive(IAsyncResult) 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 Handling and Raising Events.
