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[] bytes = new Byte[1024]; string res = string.Empty; int length = stm.Read(bytes, 0, bytes.Length); if (length > 0) { res = Encoding.UTF8.GetString(bytes, 0, length); } Console.WriteLine(res); //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。