ReceiveCompletedEventArgs Classe

Definição

public ref class ReceiveCompletedEventArgs : EventArgs

public class ReceiveCompletedEventArgs : EventArgs

type ReceiveCompletedEventArgs = class
    inherit EventArgs

Public Class ReceiveCompletedEventArgs
Inherits EventArgs

Herança

Object

EventArgs

ReceiveCompletedEventArgs

Exemplos

O exemplo de código a seguir cria um manipulador de eventos para o evento e o ReceiveCompleted associa ao delegado de eventos usando o ReceiveCompletedEventHandler. O manipulador de eventos, MyReceiveCompleted, recebe uma mensagem de uma fila e grava seu corpo na tela.

#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

Comentários

Ao usar a notificação de evento para receber mensagens de forma assíncrona da fila, você deve criar um método que manipula o processamento de mensagens. Seu código deve chamar BeginReceive para iniciar o processamento assíncrono. Quando uma mensagem é recebida, seu aplicativo é notificado por meio do ReceiveCompleted evento. Uma instância de ReceiveCompletedEventArgs é passada para o delegado de eventos que chama o manipulador de eventos. Os dados associados ao ReceiveCompleted evento estão contidos no parâmetro do AsyncResult delegado.

Há duas maneiras de fornecer notificação de conclusão do evento: notificação de eventos e retornos de chamada. ReceiveCompletedEventArgs é usado somente com notificação de evento. Para obter informações sobre como comparar retornos de chamada e notificação de eventos, consulte "Eventos vs. Retornos de chamada" no MSDN.

ReceiveCompletedEventArgs fornece acesso à mensagem que iniciou o fim da operação de recebimento assíncrono, por meio do Message membro. Esse é um acesso alternativo à mensagem e se comporta da mesma forma que uma chamada para MessageQueue.EndReceive.

Propriedades

Métodos

Aplica-se a

Confira também

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