MessageQueue.PeekCompleted MessageQueue.PeekCompleted MessageQueue.PeekCompleted MessageQueue.PeekCompleted Event

Definition

Tritt ein, wenn eine Meldung gelesen wird, ohne sie aus der Warteschlange zu entfernen.Occurs when a message is read without being removed from the queue. Dies ist ein Ergebnis eines asynchronen BeginPeek()-Vorgangs.This is a result of the asynchronous operation, BeginPeek().

public:
 event System::Messaging::PeekCompletedEventHandler ^ PeekCompleted;
[System.Messaging.MessagingDescription("MQ_PeekCompleted")]
public event System.Messaging.PeekCompletedEventHandler PeekCompleted;
member this.PeekCompleted : System.Messaging.PeekCompletedEventHandler 
Public Custom Event PeekCompleted As PeekCompletedEventHandler 
Attribute

Beispiele

Im folgenden Codebeispiel wird ein Ereignishandler mit MyPeekCompleteddem Namen erstellt, der PeekCompleted dem Ereignishandlerdelegaten angefügt wird, und es wird aufgerufen BeginPeek , um einen asynchronen Peek-Vorgang für die Warteschlange zu initiieren, die sich im Pfad ".\MyQueue" befindet.The following code example creates an event handler named MyPeekCompleted, attaches it to the PeekCompleted event handler delegate, and calls BeginPeek to initiate an asynchronous peek operation on the queue that is located at the path ".\myQueue". Wenn ein PeekCompleted -Ereignis ausgelöst wird, sieht das Beispiel die Nachricht an und schreibt Ihren Text auf den Bildschirm.When a PeekCompleted event is raised, the example peeks the message and writes its body to the screen. Im Beispiel wird dann BeginPeek erneut aufgerufen, um einen neuen asynchronen Peek-Vorgang zu initiieren.The example then calls BeginPeek again to initiate a new asynchronous peek operation

#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;

// This example performs asynchronous peek operation
// processing.
//*************************************************
ref class MyNewQueue
{
public:

   // Provides an event handler for the PeekCompleted
   // event.
   static void MyPeekCompleted( Object^ source, PeekCompletedEventArgs^ asyncResult )
   {
      // Connect to the queue.
      MessageQueue^ mq = dynamic_cast<MessageQueue^>(source);

      // End the asynchronous peek operation.
      Message^ m = mq->EndPeek( asyncResult->AsyncResult );

      // Display message information on the screen.
      Console::WriteLine( "Message: {0}", static_cast<String^>(m->Body) );

      // Restart the asynchronous peek operation.
      mq->BeginPeek();
      return;
   }
};

// Provides an entry point into the application.
//         
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 PeekCompleted event.
   myQueue->PeekCompleted += gcnew PeekCompletedEventHandler( MyNewQueue::MyPeekCompleted );

   // Begin the asynchronous peek operation.
   myQueue->BeginPeek();

   // 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 peek 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 PeekCompleted event.
            myQueue.PeekCompleted += new 
                PeekCompletedEventHandler(MyPeekCompleted);
            
            // Begin the asynchronous peek operation.
            myQueue.BeginPeek();
            
            // Do other work on the current thread.

            return;
        }


        //**************************************************
        // Provides an event handler for the PeekCompleted
        // event.
        //**************************************************
        
        private static void MyPeekCompleted(Object source, 
            PeekCompletedEventArgs asyncResult)
        {
            // Connect to the queue.
            MessageQueue mq = (MessageQueue)source;

            // End the asynchronous peek operation.
            Message m = mq.EndPeek(asyncResult.AsyncResult);

            // Display message information on the screen.
            Console.WriteLine("Message: " + (string)m.Body);

            // Restart the asynchronous peek operation.
            mq.BeginPeek();
            
            return; 
        }
    }
}
Imports System.Messaging





' Provides a container class for the example.
Public Class MyNewQueue



        ' Provides an entry point into the application.
        '		 
        ' This example performs asynchronous peek 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 PeekCompleted event.
            AddHandler myQueue.PeekCompleted, AddressOf _
                MyPeekCompleted

            ' Begin the asynchronous peek operation.
            myQueue.BeginPeek()

            ' Do other work on the current thread.
            Return
        End Sub


        '**************************************************
        ' Provides an event handler for the PeekCompleted
        ' event.
        '**************************************************

        Private Shared Sub MyPeekCompleted(ByVal [source] As _
            [Object], ByVal asyncResult As PeekCompletedEventArgs)

            ' Connect to the queue.
            Dim mq As MessageQueue = CType([source], MessageQueue)

            ' End the asynchronous peek operation.
            Dim m As Message = mq.EndPeek(asyncResult.AsyncResult)

            ' Display message information on the screen.
            Console.WriteLine(("Message: " + CStr(m.Body)))

            ' Restart the asynchronous peek operation.
            mq.BeginPeek()

            Return

        End Sub

End Class

Hinweise

BeginPeekwird bei der asynchronen Verarbeitung verwendet, um PeekCompleted das-Ereignis zu erhöhen, wenn eine Nachricht in der Warteschlange verfügbar ist.BeginPeek is used in asynchronous processing to raise the PeekCompleted event when a message is available in the queue.

EndPeek(IAsyncResult)wird verwendet, um den Vorgang abzuschließen, BeginPeek der durch einen-Rückruf initiiert wurde, und die Meldung einsehen, wenn das PeekCompleted -Ereignis ausgelöst wird.EndPeek(IAsyncResult) is used to complete the operation initiated by a call to BeginPeek and peek the message when the PeekCompleted event is raised.

Beim Erstellen eines PeekCompletedEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung.When you create a PeekCompletedEventHandler delegate, you identify the method that will handle the event. Um dem Ereignishandler das Ereignis zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu.To associate the event with your event handler, add an instance of the delegate to the event. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird.The event handler is called whenever the event occurs, unless you remove the delegate. Weitere Informationen zu Ereignishandlerdelegaten finden Sie unter behandeln und Auswerfen von Ereignissen.For more information about event handler delegates, see Handling and Raising Events.

Gilt für:

Siehe auch