public void ReceiveMessage() 
     { 
      //在本机指定的端口接收 
       IPEndPoint remoteIpEndIPoint = new IPEndPoint(IPAddress.Any,1000); 
       udpReceive = new UdpClient(remoteIpEndIPoint); 
       IPEndPoint iep = new IPEndPoint(IPAddress.Any, 0); 
       //接收从远程主机发送过来的信息 
       while (true) 
       { 
        //ref表示引用类型的 IPPoint实例接收消息 
         byte[] receiveBytes = udpReceive.Receive(ref iep); 
        for (int i = 0; i  < receiveBytes.Length; i++) 
         { 
           RetStr += String.Format("{0:X2} ", receiveBytes[i]); 
         } 
        MessageBox.Show(RetStr); 
       } 
     }