PeekCompletedEventArgs 類別

參考

定義

命名空間:: System.Messaging

組件:: System.Messaging.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

提供 PeekCompleted 事件的資料。當非同步窺視作業 (Asynchronous Peek Operation) 呼叫事件處理常式時，會將這個類別的執行個體 (Instance) 傳遞至處理常式。

public ref class PeekCompletedEventArgs : EventArgs

public class PeekCompletedEventArgs : EventArgs

type PeekCompletedEventArgs = class
    inherit EventArgs

Public Class PeekCompletedEventArgs
Inherits EventArgs

繼承: Object

EventArgs
PeekCompletedEventArgs

範例

下列程式碼範例會建立 PeekCompleted 事件的事件處理常式，並使用將它與事件委派 PeekCompletedEventHandler 產生關聯。事件處理常式 MyPeekCompleted 會查看訊息，並將其標籤寫入畫面。

#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

備註

當您使用事件通知來查看 (讀取，而不從佇列非同步移除) 訊息時，您必須建立處理訊息的方法。您的程式碼必須呼叫 BeginPeek 以開始非同步處理。查看訊息時，您的應用程式會透過 PeekCompleted 事件收到通知。的 PeekCompletedEventArgs 實例會傳遞至呼叫事件處理常式的事件委派。與事件相關聯的 PeekCompleted 資料包含在委派的 AsyncResult 參數中。

提供事件完成通知的方式有兩種：事件通知和回呼。 PeekCompletedEventArgs 僅用於事件通知。如需比較回呼和事件通知的資訊，請參閱 MSDN 上的。

PeekCompletedEventArgs 提供透過成員起始非同步查看作業結尾之訊息的 Message 存取權。這是訊息的替代存取權，其行為與呼叫 MessageQueue.EndPeek 的行為大致相同。

屬性

AsyncResult	取得或設定要求的非同步作業結果。
Message	取得與非同步窺視作業關聯的訊息。

方法

Equals(Object)	判斷指定的物件是否等於目前的物件。 (繼承來源 Object)
GetHashCode()	做為預設雜湊函式。 (繼承來源 Object)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)

適用於

PeekCompletedEventArgs 類別

定義

範例

備註

屬性

方法

適用於

另請參閱

意見反應

其他資源