本代码可直接使用 根据TCP/IP三次握手，实验时可使用两台电脑，或者打开两个终端模拟通信。

服务器端：

#include <stdio.h>  
#include <iostream>
#include <winsock2.h>  
 #include <WS2tcpip.h>
#pragma comment(lib,"ws2_32.lib")  

int main(int argc, char* argv[])  
{  
    //初始化WSA  
    WORD sockVersion = MAKEWORD(2,2);  
    WSADATA wsaData;  
    if(WSAStartup(sockVersion, &wsaData)!=0)  
    {  
        return 0;  
    }  

    //创建套接字  
    SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  
    if(slisten == INVALID_SOCKET)  
    {  
        printf("socket error !");  
        return 0;  
    }  

    //绑定IP和端口  
    sockaddr_in sin;  
    sin.sin_family = AF_INET;  
    sin.sin_port = htons(8888);  
    sin.sin_addr.S_un.S_addr = INADDR_ANY;   
    if(bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)  
    {  
        printf("bind error !");  
    }  

    //开始监听  
    if(listen(slisten, 5) == SOCKET_ERROR)  
    {  
        printf("listen error !");  
        return 0;  
    }  

    //循环接收数据  
    SOCKET sClient;  
    sockaddr_in remoteAddr;  
    int nAddrlen = sizeof(remoteAddr);  
    char revData[255];   
    while (true)  
    {  
        printf("等待连接...\n");  
        sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);  
        if(sClient == INVALID_SOCKET)  
        {  
            printf("accept error !");  
            continue;  
        }  
        printf("接受到一个连接：%s \r\n", inet_ntop(AF_INET, (void*)&remoteAddr.sin_addr, revData, 16));
       // printf("接受到一个连接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));  //inet_ntoa老函数在新版本VS+64位计算机上使用会报错

        //接收数据  
        int ret = recv(sClient, revData, 255, 0);         
        if(ret > 0)  
        {  
            revData[ret] = 0x00;  
            printf(revData);  
        }  

        //发送数据  
        const char * sendData = "你好，TCP客户端！\n";  
        send(sClient, sendData, strlen(sendData), 0);  
        closesocket(sClient);  
    }  

    closesocket(slisten);  
    WSACleanup();  
    return 0;  
} 

用户端：

#include<WINSOCK2.H>
#include<STDIO.H>
#include<iostream>
#include<cstring>
#include <WS2tcpip.h>
using namespace std;
#pragma comment(lib, "ws2_32.lib")
#pragma warning(disable:4996) //如果你有inet_addr函数的报错，加上这个就解决了
int main()
{
    WORD sockVersion = MAKEWORD(2, 2);
    WSADATA data;
    if(WSAStartup(sockVersion, &data)!=0)
    {
        return 0;
    }
    while(true){
        SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if(sclient == INVALID_SOCKET)
        {
            printf("invalid socket!");
            return 0;
        }

        sockaddr_in serAddr;
        serAddr.sin_family = AF_INET;
        serAddr.sin_port = htons(8888);
        //serAddr.sin_addr.S_un.S_addr = inet_pton(AF_INET, "127.0.0.1", &serAddr);
        serAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//如果你有inet_addr函数的报错，看上文
        if(connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
        {  //连接失败 
            printf("connect error !");
            closesocket(sclient);
            return 0;
        }

        string data;
        cin>>data;
        const char * sendData;
        sendData = data.c_str();   //string转const char* 
        //char * sendData = "你好，TCP服务端，我是客户端\n";
        send(sclient, sendData, strlen(sendData), 0);
        //send()用来将数据由指定的socket传给对方主机
        //int send(int s, const void * msg, int len, unsigned int flags)
        //s为已建立好连接的socket，msg指向数据内容，len则为数据长度，参数flags一般设0
        //成功则返回实际传送出去的字符数，失败返回-1，错误原因存于error 

        char recData[255];
        int ret = recv(sclient, recData, 255, 0);
        if(ret>0){
            recData[ret] = 0x00;
            printf(recData);
        } 
        closesocket(sclient);
    }


    WSACleanup();
    return 0;

}

工具->编译选项->在连接器命令行加入如下命令里面添加-lwsock32 即可

两个程序的原理本质是一样的网上有很多类似的原理介绍，这里不再赘述，只需要按照这个原理图，一步步实现代码即可。

此外遇到的一些新版本VS编译的问题，在代码注释中已经给出答案了，完美运行哦~