private void BeginListen()
        {
            serverIP = IPAddress.Parse(tbxIP.Text);
            serverFullAddr = new IPEndPoint(serverIP, int.Parse(tbxPort.Text));//设置IP，端口
            sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //指定本地主机地址和端口号
            sock.Bind(serverFullAddr);
            lbxMessage.Invoke(new SetTextCallback(SetText), "启动成功 时间:"+DateTime.Now, 1);
            byte[] message = new byte[1024];
            string mess = "";
            while (true)
            {
                try
                {
                    sock.Listen(5);//设置监听频率
                    Socket newSocket = sock.Accept();//阻塞方式
                    int bytes=  newSocket.Receive(message);//接收数据
                    mess = Encoding.Default.GetString(message, 0, bytes);//对接收字节编码（S与C 两端编码格式必须一致不然中文乱码）（当接收的字节大于1024的时候 这应该是循环接收，测试就没有那样写了）
                    //do
                    //{
                    //    bytes = newSocket.Receive(message, message.Length, 0);
                    //    mess = mess + Encoding.ASCII.GetString(message, 0, bytes);
                    //}
                   // while (bytes > 0);

                    lbxMessage.Invoke(new SetTextCallback(SetText),mess,1);//子线程操作主线程UI控件
                    mess = "已接收数据： " + mess + " 当前时间为：" + DateTime.Now;
                    newSocket.Send(Encoding.Default.GetBytes(mess));//想客户端发送数据

                }
                catch (SocketException se)
                {
                    lbxMessage.Invoke(new SetTextCallback(SetText), mess, 1);

                }
            }
        }

  //发送消息
        private void btnSend_Click(object sender, EventArgs e)
        {
            serverFullAddr = new IPEndPoint(serverIP, int.Parse(tbxPort.Text));//设置IP，端口
            sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //指定本地主机地址和端口号
            sock.Connect(serverFullAddr);
            byte[] byteSend = System.Text.Encoding.Default.GetBytes(this.tbxMessage.Text);
            byte[] message = new byte[1024];
            string mess = "";
            int bytes = 0;
            try
            {
                //发送数据
                sock.Send(byteSend);
               
                bytes = sock.Receive(message);//接收数据
                mess = mess + Encoding.Default.GetString(message,0,bytes);//编码（当接收的字节大于1024的时候 这应该是循环接收，测试就没有那样写了）
                //do
                //{
                //    bytes = newSocket.Receive(message, message.Length, 0);
                //    mess = mess + Encoding.ASCII.GetString(message, 0, bytes);
                //}
                // while (bytes > 0);
                tbxMessage.Text = mess; 
            }
            catch (Exception ex)
            {
                lblError.Text = "出现错误，请联系管理员";
            }
            sock.Close();
        }

  static void Main(string[] args)
        {
            TcpListener listener = null;
            int