ReceiveCompletedEventArgs Klass

Definition

public ref class ReceiveCompletedEventArgs : EventArgs

public class ReceiveCompletedEventArgs : EventArgs

type ReceiveCompletedEventArgs = class
    inherit EventArgs

Public Class ReceiveCompletedEventArgs
Inherits EventArgs

Arv

Object

EventArgs

ReceiveCompletedEventArgs

Exempel

Följande kodexempel skapar en händelsehanterare för ReceiveCompleted händelsen och associerar den med händelsedelegaten ReceiveCompletedEventHandlermed hjälp av . Händelsehanteraren, MyReceiveCompleted, tar emot ett meddelande från en kö och skriver dess brödtext till skärmen.

#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

Kommentarer

När du använder händelsemeddelande för att ta emot meddelanden asynkront från kön måste du skapa en metod som hanterar meddelandebearbetningen. Koden måste anropas BeginReceive för att påbörja den asynkrona bearbetningen. När ett meddelande tas emot meddelas ditt program via ReceiveCompleted händelsen. En instans av ReceiveCompletedEventArgs skickas till händelsedelegaten som anropar händelsehanteraren. De data som är associerade med ReceiveCompleted händelsen finns i ombudets AsyncResult parameter.

Det finns två sätt att tillhandahålla meddelande om händelseavisering och återanrop. ReceiveCompletedEventArgs används endast med händelsemeddelande. Information om hur du jämför motringningar och händelsemeddelanden finns i "Händelser kontra återanrop" på MSDN.

ReceiveCompletedEventArgs ger åtkomst till meddelandet som initierade slutet av den asynkrona mottagningsåtgärden Message via medlemmen. Det här är en alternativ åtkomst till meddelandet och fungerar ungefär som ett anrop till MessageQueue.EndReceive.

Se även

• MessageQueue
• ReceiveCompletedEventHandler
• ReceiveCompleted
• BeginReceive()
• EndReceive(IAsyncResult)
• Message