udp的数据不能接收，求解

C# code

 int port = int.Parse(textBox2.Text);               textBox1.AppendText("连接等待.........");            UdpClient receivingUdpClient = new UdpClient(port);//创建UDPClient对象            IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, port);//创建IPEndPoint对象            while(true)            {                    Byte[] receiveBytes = receivingUdpClient.Receive(ref RemoteIpEndPoint);//接收远程发送的UDP数据报,就是卡在这儿了                    if (receiveBytes.Length > 0)                    {                        string returnData = Encoding.ASCII.GetString(receiveBytes);//将字节数组转换为字符串                        textBox1.AppendText("This is the message you received " +//输出字符串信息                                                    returnData.ToString());                        textBox1.AppendText("This message was sent from " +//输出远程主机地址及发送数据报使用的端口                                                    RemoteIpEndPoint.Address.ToString() +                                                    " on their port number " +                                                    RemoteIpEndPoint.Port.ToString());                        DateTime currentTime = DateTime.Now;                        string strtime = currentTime.Hour.ToString() + ":" + currentTime.Minute.ToString() + ":"                                          + currentTime.Second.ToString() + ":"                                          + currentTime.Millisecond.ToString();                        byte[] mybyte = Encoding.Default.GetBytes(strtime);                        receivingUdpClient.Send(mybyte, strtime.Length, RemoteIpEndPoint);                    }              }                }