Socket编程服务器和客户端（多个客户端可以同时连接一个服务器的同一端口）

服务器端代码

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace TCP通信
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                //把ip地址转换为实例
                IPAddress ipa = IPAddress.Parse("127.0.0.1");
                //监听端口8001
                TcpListener mylsn = new TcpListener(ipa, 8001);
                //开启监听
                mylsn.Start();
                //输出监听成功的信息
                Console.WriteLine("在8001启动服务，等待连接");
                //等待处理接入连接请求
                while (true)
                {
                    Socket mysock = mylsn.AcceptSocket();
                    Console.WriteLine("有连接，连接来自" + mysock.RemoteEndPoint);
                    work w = new work();
                    w.mysock = mysock;
                    w.mylsn = mylsn;
                    Thread t = new Thread(new ThreadStart(w.main));
                    t.Start();
                }
            }
            catch
            { }
            finally
            { }
        }
    }
    public class work
    {
        public Socket mysock;
        public TcpListener mylsn;
        public void main()
        {
            //接收客户端消息
            byte[] data = new byte[100];
            mysock.Receive(data);
            string rt = System.Text.UTF8Encoding.UTF8.GetString(data);
            Console.WriteLine(rt);
            //给客户端发消息
            mysock.Send(UTF8Encoding.UTF8.GetBytes("回发给客户端"));
            //释放资源
            mysock.Close();
            mylsn.Stop();
        }
    }
}

 

客户端代码

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
namespace TCP通信客户端
{
    public class Class1
    {
        public static void Main()
        {
            //新建客户端套接字
            TcpClient tclient = new TcpClient();
            //连接服务器
            tclient.Connect("127.0.0.1", 8001);
            Console.WriteLine("输入要发送的消息");
            //读入要传输的字符
            string str = Console.ReadLine();

            //得到流
            Stream stm = tclient.GetStream();
            //发送字符串
            ASCIIEncoding asen = new ASCIIEncoding();
            byte[] data = asen.GetBytes(str);
            stm.Write(data, 0, data.Length);
            //接受服务器返回的消息
            byte[] back = new byte[100];
            int k = stm.Read(back, 0, 100);
            //输出服务器返回的消息
            for (int i = 0; i < k; i++)
            {
                Console.Write(Convert.ToChar(back[i]));
            }
            //关闭连接
            tclient.Close();
        }
    }
}

 

根据TCP/IP设计者的设计初衷，当mysock.Close()以后用命令netstat -a -n查看本地连接的时候对应的链接状态为 TIME_WAIT。该连接由系统自动关闭。