C#网络通信（2）--TCP编程和多线程

IPAddress local = IPAddress.Any;
            IPEndPoint iep = new IPEndPoint(local, 13000);
            server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            // 将套接字与本地终结点绑定	
            server.Bind(iep);

            //在本地13000端口号上进行监听	
            server.Listen(20);
            Console.WriteLine("等待客户机进行连接......");
            while (true)
            {
                // 得到包含客户端信息的套接字
                Socket client = server.Accept();

                //创建消息服务线程对象
                ClientThread newclient = new ClientThread(client);

                //把ClientThread 类的ClientService方法委托给线程
                Thread newthread = new Thread(new ThreadStart(newclient.ClientService));

                // 启动消息服务线程
                newthread.Start();

class ClientThread
    {
        //connections变量表示连接数
        public static int connections = 0;
        public Socket service;
        int i;
        public ClientThread(Socket clientsocket)
        {
            //service对象接管对消息的控制
            this.service = clientsocket;
        }
        public void ClientService()
        {
            String data = null;
            byte[] bytes = new byte[1024];
            if (service != null)
            {
                connections++;
            }
            Console.WriteLine("新客户连接建立:{0} 个连接数", connections);
            while ((i = service.Receive(bytes)) != 0)
            {
                data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
                Console.WriteLine("收到的数据: {0}", data);

                // 处理客户端发来的消息，这里是转化为大写字母
                data = data.ToUpper();
                byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);

                // 发送一条应答消息
                service.Send(msg);
                Console.WriteLine("发送的数据: {0}", data);
            }
            //关闭套接字
            service.Close();
            connections--;
            Console.WriteLine("客户关闭连接:{0} 个连接数", connections);
        }
    }