static void Main(string[] args)
        {
            TcpClient client = null;
            NetworkStream stream = null;
            byte[] buffer = null;
            string receiveString = null;

            IPAddress localIP = IPAddress.Parse("127.0.0.1");
            int localPort = 11000;
            TcpListener listener = new TcpListener(localIP, localPort);//用本地IP和端口实例化Listener
            listener.Start();//开始监听
            while (true)
            {
                client = listener.AcceptTcpClient();//接受一个Client
                buffer = new byte[client.ReceiveBufferSize];
                stream = client.GetStream();//获取网络流
                stream.Read(buffer, 0, buffer.Length);//读取网络流中的数据
                stream.Close();//关闭流
                client.Close();//关闭Client

                receiveString = Encoding.Default.GetString(buffer).Trim('\0');//转换成字符串
                Console.WriteLine(receiveString);
            }
        }

static void Main(string[] args)
        {
            string sendString = null;//要发送的字符串
            byte[] sendData = null;//要发送的字节数组
            TcpClient client = null;//TcpClient实例
            NetworkStream stream = null;//网络流

            IPAddress remoteIP = IPAddress.Parse("127.0.0.1");//远程主机IP
            int remotePort = 11000;//远程主机端口

            while (true)//死循环
            {
                sendString = Console.ReadLine();//获取要发送的字符串
                sendData = Encoding.Default.GetBytes(sendString);//获取要发送的字节数组
                client = new TcpClient();//实例化TcpClient
                try
                {
                    client.Connect(remoteIP, remotePort);//连接远程主机
                }
                catch (System.Exception ex)
                {
                    Console.WriteLine("连接超时，服务器没有响应！");//连接失败
                    Console.ReadKey();
                    return;
                }
                stream = client.GetStream();//获取网络流
                stream.Write(sendData, 0, sendData.Length);//将数据写入网络流
                stream.Close();//关闭网络流
                client.Close();//关闭客户端
            }
        }