基于Windows套接字Socket，简单的面向连接的TCP服务器和客户机，实例：

         简单的TCP服务器：

                在服务器能够向客户机连接传输数据之前，必须做以下几件事情：

                1： 创建一个套接字；

                2：将所创建的套接字与本地的IPEndPoint绑定；

                3：设置套接字为收听模式；

                4：在套接字上接受接入的连接。

                源程序如下：程序在VS2005中调试通过

using System;
using System.Collections.Generic;
using System.Text;

using System.Net;
using System.Net.Sockets;

namespace FixedTcpServer
{
    class Program
    {
        /// <summary>
        /// 发送数据
        /// </summary>
        /// <param name="s">发送数据的套接字</param>
        /// <param name="data">缓冲区</param>
        /// <returns></returns>
        private static int SendData(Socket s, byte[] data)
        {
            int total = 0;
            int size = data.Length;
            int dataleft = size;
            int sent;

            while (total < size)
            {
                sent = s.Send(data, total, SocketFlags.None);
                total += sent;
                dataleft -= sent;
            }
            return total;
        }
        /// <summary>
        /// 接受数据
        /// </summary>
        /// <param name="s">接受数据的套接字</param>
        /// <param name="size"></param>
        /// <returns></returns>
        private static byte[] ReceiveData(Socket s, int size)
        {
            int total = 0;
            int dataleft = size;
            byte[] data = new byte[size];
            int recv;

            while (total < size)
            {
                recv = s.Receive(data, total, dataleft, 0);
                if (recv == 0)
                {
                    data = Encoding.ASCII.GetBytes("exit");
                    break;
                }
                total += recv;
                dataleft -= recv;
            }
            return data;
        }

        static void Main(string[] args)
        {

            byte[] data = new byte[1024];//定义缓冲区
            //定义一个服务器
            IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 9050);
            Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //绑定并且开始监听
            newsock.Bind(ipep);
            newsock.Listen(10);

            Console.WriteLine("Waiting for a client....");
            //接受客户端的连接请求
            Socket client = newsock.Accept();

            //利用新定义的套接字接受客户端连接请求的返回值来输出客户端的IP，端口信息
            IPEndPoint newclient = (IPEndPoint)client.RemoteEndPoint;
            Console.WriteLine("Connected with {0} at port {1}", newclient.Address, newclient.Port);

            //向客户端发送欢迎信息
            string welcome = "Welcome to my test server";
            data = Encoding.ASCII.GetBytes(welcome);
            int sent = SendData(client, data);//调用发送信息函数

            for (int i = 0; i < 5; i++)
            {
                data = ReceiveData(client, 9);
                Console.WriteLine(Encoding.ASCII.GetString(data));
            }
            Console.WriteLine("Disconnected from {0}", newclient.Address);
            client.Close();
            newsock.Close();
        }
    }
}

 

         简单的TCP客户机：

                基于上面的TCP服务器，因此可以创建一个简单的TCP客户机与它进行通信。

                创建与TCP服务器相连的客户机如下：

                1：创建一个套接字；

                2：将套接字与远程服务器地址相连。

                源代码如下：此程序在VS2005中调试通过。

using System;
using System.Collections.Generic;
using System.Text;

using System.Net;
using System.Net.Sockets;

namespace FixedTcpClient
{
    class Program
    {
        private static int SendData(Socket s, byte[] data)
        {
            int total = 0;
            int size = data.Length;
            int dataleft = size;
            int sent;

            while (total < size)
            {
                sent = s.Send(data, total, dataleft, SocketFlags.None);
                total += sent;
                dataleft -= sent;
            }
            return total;
        }

        private static byte[] ReceiveData(Socket s, int size)
        {
            int total = 0;
            int dataleft = size;
            byte[] data = new byte[size];

            int recv;
            while (total < size)
            {
            }
        }

        static void Main(string[] args)
        {
        }
    }
}

       以上程序可以在一台电脑中进行测试，先打开服务器，再打开客户机。希望这两个程序能帮网友理解一点的Socket知识。由于工作原因只是放上两个程序的源码。具体解释，可以看MSDN，希望网友们不要骂我。