ReceiveCompletedEventArgs 类

定义

命名空间:

System.Messaging

程序集:

System.Messaging.dll

为 ReceiveCompleted 事件提供数据。 当异步接收操作调用事件处理程序时，此类的一个实例将被传递给该处理程序。

public ref class ReceiveCompletedEventArgs : EventArgs

public class ReceiveCompletedEventArgs : EventArgs

type ReceiveCompletedEventArgs = class
    inherit EventArgs

Public Class ReceiveCompletedEventArgs
Inherits EventArgs

继承

Object

EventArgs

ReceiveCompletedEventArgs

示例

下面的代码示例为 事件创建事件处理程序， ReceiveCompleted 并使用 ReceiveCompletedEventHandler将其与事件委托相关联。 事件处理程序 MyReceiveCompleted从队列接收消息，并将其正文写入屏幕。

#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

注解

使用事件通知从队列异步接收消息时，必须创建处理消息处理的方法。 代码必须调用 BeginReceive 才能开始异步处理。 收到消息时，将通过 事件通知 ReceiveCompleted 应用程序。 的 ReceiveCompletedEventArgs 实例将传递到调用事件处理程序的事件委托中。 与事件关联的 ReceiveCompleted 数据包含在委托的 AsyncResult 参数中。

可通过两种方式提供事件完成通知：事件通知和回调。 ReceiveCompletedEventArgs 仅用于事件通知。 有关比较回调和事件通知的信息，请参阅 MSDN 上的“事件与回调”。

ReceiveCompletedEventArgs 通过 Message 成员提供对启动异步接收操作结束的消息的访问权限。 这是对消息的备用访问，其行为与对 的调用 MessageQueue.EndReceive大致相同。

属性

AsyncResult	获取或设置请求的异步操作结果。
Message	获取同异步接收操作关联的消息。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

另请参阅

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