using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Net;
using System.Net.Sockets;namespace SocketTest
{public partial class Server : Form{Thread serverThread; //服务端线程Thread clientThread; //客户端线程Socket serverSocket; //服务端socketSocket clientSocket; //客户端socketpublic Server(){InitializeComponent();}private void ServerStart(){//创建IPEndPoint实例IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 6001);//创建一个套接字serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//将所创建的套接字与IPEndPoint绑定
            serverSocket.Bind(ipep);//设置套接字为收听模式serverSocket.Listen(10);/*** 通过serverSocket.Accept()来接收客户Socket的连接请求，* 在这里用循环可以实现该线程实时侦听，而不是只侦听一次。* 当程序运行serverSocket.Accept()时，会等待，直到有客户端Socket发起连接请求时，* 获取该客户Socket，如上面的clientSocket。在这里我用多线程来实现与多个客户端Socket的连接和通信，* 一旦接收到一个连接后，就新建一个线程，执行ReceiveData功能来实现信息的发送和接收。*/while (true){try{//在套接字上接收接入的连接clientSocket = serverSocket.Accept();clientThread = new Thread(new ThreadStart(ReceiveData));clientThread.Start();}catch (Exception ex){MessageBox.Show("listening Error: " + ex.Message);}}}/*** 通过IPEndPoint clientep = (IPEndPoint)s.RemoteEndPoint;* 我们可以获取连接上的远程主机的端口和IP地址，如果想查询该主机的其它属性如主机名等，* 可用于上一篇讲的Dns.GetHostByAddress(string ipAddress)来返回一个IPHostEntry对象，就可以得到。* 另外我们要注意的是，通过Socket发送信息，必须要先把发送的信息转化成二进字进行传输，* 收到信息后也要把收到的二进字信息转化成字符形式，* 这里可以通过Encoding.ASCII.GetBytes(welcome);和Encoding.ASCII.GetString(buffer).Substring(0, bufLen);来实现。* 以上就是服务端Socket侦听模式的实现，只要有远程客户端Socket连接上后，就可以轻松的发送信息和接收信息了。* 下面我们来看看客户端Socket是怎么连接上服务器的。**/private void ReceiveData(){bool keepalive = true;Socket s = clientSocket;Byte[] buffer = new Byte[1024];//根据收听到的客户端套接字向客户端发送信息IPEndPoint clientep = (IPEndPoint)s.RemoteEndPoint;this.Invoke(new MethodInvoker(() =>{lstServer.Items.Add("Client：" + clientep.Address + "(" + clientep.Port + ")");}));string welcome = "Welcome to my test sever ";byte[] data = new byte[1024];data = Encoding.ASCII.GetBytes(welcome);s.Send(data, data.Length, SocketFlags.None);while (keepalive){//在套接字上接收客户端发送的信息int bufLen = 0;try{bufLen = s.Available;s.Receive(buffer, 0, bufLen, SocketFlags.None);if (bufLen == 0)continue;}catch (Exception ex){MessageBox.Show("Receive Error:" + ex.Message);return;}clientep = (IPEndPoint)s.RemoteEndPoint;string clientcommand = System.Text.Encoding.ASCII.GetString(buffer).Substring(0, bufLen);this.Invoke(new MethodInvoker(() =>{lstServer.Items.Add(clientcommand + "(" + clientep.Address + ":" + clientep.Port + ")");}));}}private void btnOpen_Click(object sender, EventArgs e){serverThread = new Thread(new ThreadStart(ServerStart));serverThread.Start();lstServer.Items.Add("Server Start .....");}}
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;namespace Client
{public partial class Client : Form{Socket clientSocket;Thread clientThread;public Client(){InitializeComponent();}/*** 客户端Socket连接相对来说比较简单了，另外说明一下，在执行客户端连接前，服务端Socket侦听必须先启动，* 不然会提示服务器拒绝连接的信息。* 客户端的发送信息和接收信息跟服务器的接收发送是一样的，只不过一个是侦听模式而另一个是连接模式。* 另外提一下，这里服务端开启侦听服务、客户端连接服务端都采用线程方式来实现，这样服务端能够跟多个客户端同时通信，不用等候，* 当然还有另外一种方式可以实现那就是异步socket.*/private void ConnectToServer(){byte[] data = new byte[1024];//创建一个套接字IPEndPoint ipep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 6001);clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//将套接字与远程服务器地址相连try{clientSocket.Connect(ipep);}catch (SocketException ex){MessageBox.Show("connect error: " + ex.Message);return;}while (true){//接收服务器信息int bufLen = 0;try{bufLen = clientSocket.Available;clientSocket.Receive(data, 0, bufLen, SocketFlags.None);if (bufLen == 0){continue;}}catch (Exception ex){MessageBox.Show("Receive Error:" + ex.Message);return;}string clientcommand = System.Text.Encoding.ASCII.GetString(data).Substring(0, bufLen);this.Invoke(new MethodInvoker(() =>{lstClient.Items.Add(clientcommand);}));//clientSocket.Shutdown(SocketShutdown.Both);//clientSocket.Close();
            }}private void button1_Click(object sender, EventArgs e){clientThread = new Thread(new ThreadStart(ConnectToServer));clientThread.Start();}private void btnSend_Click(object sender, EventArgs e){//向服务器发送信息byte[] data = new byte[1024];data = Encoding.ASCII.GetBytes(txtClient.Text);clientSocket.Send(data, data.Length, SocketFlags.None);}}
}