收听msmq队列

Question

以下是我用于收听Windows窗体消息的代码。

我注意到，当我点击send它发送消息给MyQueue，但当时我希望事件mq_ReceiveCompleted(object sender, ReceiveCompletedEventArgs e)应该被调用，但它不是，换句话说，我试图从Windows窗体订阅MyQueue 。只是想知道我是否遗漏了代码中的某些东西：

public class Form1 : System.Windows.Forms.Form 
{ 
    public System.Messaging.MessageQueue mq; 
    public static Int32 j=0; 

    public Form1() 
    { 
     // Required for Windows Form Designer support 
     InitializeComponent(); 

     // Queue Creation 
     if(MessageQueue.Exists(@".\Private$\MyQueue")) 
     mq = new System.Messaging.MessageQueue(@".\Private$\MyQueue"); 
     else 
     mq = MessageQueue.Create(@".\Private$\MyQueue"); 

     mq.ReceiveCompleted += new ReceiveCompletedEventHandler(mq_ReceiveCompleted); 
     mq.BeginReceive(); 
    } 

    [STAThread] 
    static void Main() 
    { 
     Application.Run(new Form1()); 
    } 

    private void btnMsg_Click(object sender, System.EventArgs e) 
    { 
     // SendMessage(Handle, 1, 0, IntPtr.Zero); 
     System.Messaging.Message mm = new System.Messaging.Message(); 
     mm.Body = txtMsg.Text; 
     mm.Label = "Msg" + j.ToString(); 
     j++; 
     mq.Send(mm); 
    } 

    void mq_ReceiveCompleted(object sender, ReceiveCompletedEventArgs e) 
    { 
     //throw new NotImplementedException(); 
    } 

    private void btnRcv_Click(object sender, System.EventArgs e) 
    { 
     System.Messaging.Message mes; 
     string m; 

     try 
     { 
      mes = mq.Receive(new TimeSpan(0, 0, 3)); 
      mes.Formatter = new XmlMessageFormatter(new String[] {"System.String,mscorlib"}); 
      m = mes.Body.ToString(); 
     } 
     catch 
     { 
      m = "No Message"; 
     } 
     MsgBox.Items.Add(m.ToString()); 
    } 
} 

Answer 1

请参阅MSDN's example on how to use the ReceiveCompletedEventHandler。

他们有一个控制台应用程序，其中Main()与Form1()的作用相同，但您的处理程序没有任何代码。你已经说过它不会回调你的事件委托，但是也许在构造函数中检查你的队列名是否正确。

使用一个新的控制台应用程序 MSDN的示例代码首先测试您的环境，然后回到你的WinForms代码与任何教训考虑。

private static void MyReceiveCompleted(Object source, 
     ReceiveCompletedEventArgs asyncResult) 
    { 
     MessageQueue mq = (MessageQueue)source; 
     Message m = mq.EndReceive(asyncResult.AsyncResult); 

     Console.WriteLine("Message: " + (string)m.Body); 
     mq.BeginReceive();  
     return; 
    } 

如果要检查队列并获得一个点击按钮的消息，你可以简单地声明mq.BeginReceive();移动到位的.Receive()的btnRcv_Click();