核心：
在服务器端和客户端的两个Socket实例，共同维持一个连接，而我们还需要一个服务端绑定了特定端口号的固定的serverSocket，用来监听远方clientSocket的申请，并为这个申请建立服务端对应的proxSocket
服务器维护：
serverSocket
| 服务端实例 | 客户端实例 | 关系 |
|---|---|---|
| proxSocket | clientSocket | 一一对应 |
一、要有服务端
--配置--
1、new Socket
Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
2、Bind
ServerSocket.Bind(new IPEndPoint(IPAddress.Parse(txtIP), int.Parse(txtPost))); //服务器绑定本机IP和端口
3、Listen
ServerSocket.Listen(10); //最大连接数是10
4、Accept
Socket proxSocket = ServerSocket.Accept(); //监听Socket连接行为，并为监听到的链接创建Socket实例，会阻塞线程直到端口链接
--信息发送与传输--
5、Receive
proxSocket.Receive(data, 0, data.Length, SocketFlags.None); //data是要写入的byte数组，会阻塞线程直到侦听到slientSocket的Send并持续到IO结束
6、Send
proxSocket.Send(result, 0, result.Length, SocketFlags.None); //result是要上传的byte数组
二、还有客户端
--配置--
1、new Socet
ClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
2、Connect
ClientSocket.Connect(new IPEndPoint(IPAddress.Parse(txtIP), int.Parse(txtPort))); //尝试链接服务器的相应IP和端口，连接成功后，服务器端创建一个特定的proxSocket用来进行信息交换
--信息发送与传输--
3
ClientSocket.Receive(data, 0, data.Length, SocketFlags.None);
4
ClientSocket.Send(result, 0, result.Length, SocketFlags.None);
三、简单实现
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;namespace SockerDamo
{class SocketServer{List<Socket> ClientProxSocketList = new List<Socket>();//用于存放客户端链接Socket ServerSocket { get; set; }public void Start()//创建服务器Socket，开始侦听客户端，并开始循环接收消息{//1.创建socket对象Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);ServerSocket = serverSocket;//first is 寻址方式(此处是Ipv4)//second is the socket's type//And the thrid is the 传输协议System.Console.WriteLine("请输入IP地址：");String txtIP = Console.ReadLine();System.Console.WriteLine("请输入端口号：");String txtPost = Console.ReadLine();//2.绑定端口IPServerSocket.Bind(new IPEndPoint(IPAddress.Parse(txtIP), int.Parse(txtPost)));//socket's Bind action need a IPEndPoint to bind the socket and the computer's ip and post//so in the IPEndPoint we need a IPAddress and a int number(Post)//3.开始侦听ServerSocket.Listen(20);//the number 表示 同时排队的最大限制数量//同时来了100个链接请求，只能处理一个链接，队列里面放20个等待链接的客户端，其他的返回错误消息。//4.开始接受客户端的链接//为了不阻塞主线程,我们应该把以下代码放在一个新的线程(池)中try{System.Console.WriteLine("开始监听链接...");Socket proxSocket = ServerSocket.Accept();//这个方法会阻塞当前线程，直到监听到链接AppendTextToTxtLog(string.Format("客户端{0}已链接", proxSocket.RemoteEndPoint.ToString()));byte[] data = new byte[1024 * 1024 * 256];//用来放数据的数组int len;while (true){System.Console.WriteLine("请选择模式：");System.Console.WriteLine("0.等待接收消息");System.Console.WriteLine("1.发送消息");string mo = Console.ReadLine();//获取客户端数据并返回读取的字节数,会阻塞当前线程,//当客户端突然掉线,往往会引发异常if (mo == "0"){try{len = proxSocket.Receive(data, 0, data.Length, SocketFlags.None);//往data数组里，从index=0开始，最长写入数据长度为data.Lengthif (data[0] == 0){StopConnect(proxSocket);}//正常退出逻辑else if (data[0] == 1){string str = Encoding.UTF8.GetString(data, 1, len - 1);//在data数组中从0开始，len个数据，转成strAppendTextToTxtLog(string.Format("接收到客户端:{0} 的信息是:{1}", proxSocket.RemoteEndPoint.ToString(), str));}}catch (Exception){Console.WriteLine("接收数据出错");StopConnect(proxSocket);}}else if (mo == "1"){SendMsg();}}}catch{AppendTextToTxtLog("出问题啦:您在接收客户端的请求的时候,发生了异常,夭寿啦```");}}private void StopConnect(Socket proxSocket)//停止链接{try{if (proxSocket.Connected){proxSocket.Shutdown(SocketShutdown.Both);proxSocket.Close(100);}}catch (Exception ex){System.Console.WriteLine("或许没有成功的停止连接" + ex.ToString());}}//发送消息private void SendMsg(){String txtMsg = Console.ReadLine();foreach (var proxSocket in ClientProxSocketList){if (proxSocket.Connected){byte[] data = Encoding.UTF8.GetBytes(txtMsg);//信息转二进制byte[] result = new byte[data.Length + 1];//信息的二进制放在1~data.Lengthresult[0] = 1;//第0个位置是标志位，将来我们可以用这个标志位，分辨文件类型，将来用来传文件Buffer.BlockCopy(data, 0, result, 1, data.Length);//把 data从0 转 result从1 长度data.Length proxSocket.Send(result, 0, result.Length, SocketFlags.None);//发送消息}}AppendTextToTxtLog(string.Format("{0}(本机) 的信息是:{1}", ServerSocket.LocalEndPoint.ToString(), txtMsg));}private void AppendTextToTxtLog(string txt){Console.WriteLine(txt);}}class SocketClient{Socket ClientSocket { get; set; }public void Start()//创建客户端Socket，并开始循环接收消息{#region 获取服务器端口内容System.Console.WriteLine("请输入服务器IP：");String txtIP = Console.ReadLine();System.Console.WriteLine("请输入端口号：");String txtPort = Console.ReadLine();#endregion//客户端链接服务器端//1.创建Socket对象ClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//2.连接服务器端Sockettry//如果服务器的Listen队列已满,那么就会返回一个异常{ClientSocket.Connect(new IPEndPoint(IPAddress.Parse(txtIP), int.Parse(txtPort)));}catch{System.Console.WriteLine("当前服务器无法连接");//Thread.Sleep(1000);return;}//3.接收服务器端消息byte[] data = new byte[1024 * 1024 * 256];//传输数据放在这里，这里是256MB = 256 * 1024 KB = 256 * 1024 * 1024Byte int len;string str;string wenJianMing = "";while (true){System.Console.WriteLine("请选择模式：");System.Console.WriteLine("0.等待接收消息");System.Console.WriteLine("1.发送消息");string mo = Console.ReadLine();len = 0;str = null;if (mo == "0")try{len = ClientSocket.Receive(data, 0, data.Length, SocketFlags.None);//获取服务器端数据并返回读取的字节数,会阻塞当前线程,//当客户端突然掉线,往往会引发异常if (data[0] == 0)//模式0退出{AppendTextToTxtLog(string.Format("服务端:{0} 正常退出", ClientSocket.RemoteEndPoint.ToString()));StopConnect();}else if (data[0] == 1){//模式1收到了字符串str = Encoding.UTF8.GetString(data, 1, len - 1);AppendTextToTxtLog(string.Format("Socket信息:{0}", str));}//一次类推，总共有256种消息的传输模式}catch (Exception){AppendTextToTxtLog(string.Format("服务端:{0} 非正常退出",ClientSocket.RemoteEndPoint.ToString()));StopConnect();return;}else if(mo == "1"){SendMsg();}}// 也可以将第3步写入方法ReceiveData// Thread thread = new Thread(new ParameterizedThreadStart(ReceiveData));// thread.IsBackground = true;// thread.Start(); // 然后开启线程}private void AppendTextToTxtLog(string txt){Console.WriteLine(txt);}private void StopConnect(){try{if (ClientSocket.Connected){ClientSocket.Shutdown(SocketShutdown.Both);ClientSocket.Close(100);}}catch (Exception ex){System.Console.WriteLine("或许没有成功的停止连接" + ex.ToString());}}public void SendMsg(){if (ClientSocket.Connected){System.Console.WriteLine("请输入要发送信息的模式：");System.Console.WriteLine("0：结束");System.Console.WriteLine("1：字符串");String ms = Console.ReadLine();if (ms == "0") { }if (ms == "1"){System.Console.WriteLine("请输入要发送的消息：");String s = Console.ReadLine();byte[] data = Encoding.UTF8.GetBytes(s);byte[] result = new byte[data.Length + 1];//信息的二进制放在1~data.Lengthresult[0] = 1;//第0个位置是标志位，将来我们可以用这个标志位，分辨文件类型，将来用来传文件Buffer.BlockCopy(data, 0, result, 1, data.Length);//把 data从0 转 result从1 长度data.Length ClientSocket.Send(result, 0, result.Length, SocketFlags.None);//发送消息AppendTextToTxtLog(string.Format("本机的信息是:{0}", s));}}}}internal class Program{static void Main(string[] args){System.Console.WriteLine("0：服务器端");System.Console.WriteLine("1：客户端");string ms = Console.ReadLine();if (ms == "0"){SocketServer server = new SocketServer();server.Start();}else if (ms == "1"){SocketClient client = new SocketClient();client.Start();}}}
}
