MessageQueue.ReceiveCompleted 事件

定義

發生於從佇列移除訊息時。Occurs when a message has been removed from the queue. 這個事件是由非同步作業 BeginReceive() 所引發。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;
member this.ReceiveCompleted : System.Messaging.ReceiveCompletedEventHandler 
Public Custom Event ReceiveCompleted As ReceiveCompletedEventHandler 
屬性

範例

下列程式碼範例會建立名為MyReceiveCompleted的事件處理常式、將它附加ReceiveCompleted至事件處理常式BeginReceive委派, 並呼叫, 以在位於路徑 ".\myQueue" 的佇列上起始非同步接收作業。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". 當引發ReceiveCompleted事件時, 此範例會接收訊息, 並將其主體寫入螢幕。When a ReceiveCompleted event is raised, the example receives the message and writes its body to the screen. 然後, 此範例BeginReceive會再次呼叫以起始新的非同步接收作業。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

備註

BeginReceive當佇列中有可用的訊息時ReceiveCompleted , 會在非同步處理中用來引發事件。BeginReceive is used in asynchronous processing to raise the ReceiveCompleted event when a message is available in the queue.

EndReceive(IAsyncResult)是用來完成呼叫BeginReceive所起始的作業, 並ReceiveCompleted在引發事件時查看訊息。EndReceive(IAsyncResult) is used to complete the operation initiated by a call to BeginReceive and peek the message when the ReceiveCompleted event is raised.

建立 ReceiveCompletedEventHandler 委派時,必須識別處理事件的方法。When you create a ReceiveCompletedEventHandler delegate, you identify the method that will handle the event. 若要使事件與您的事件處理常式產生關聯,請將委派的執行個體 (Instance) 加入至事件。To associate the event with your event handler, add an instance of the delegate to the event. 除非您移除委派,否則每當事件發生時就會呼叫事件處理常式。The event handler is called whenever the event occurs, unless you remove the delegate. 如需事件處理常式委派的詳細資訊, 請參閱處理和引發事件For more information about event handler delegates, see Handling and Raising Events.

適用於

另請參閱