发送结构化的网络消息数据

流程图：

将字符串消息类型变为结构体类型的消息进行发送和接收！

服务器端：

#include<WinSock2.h>
#include<Windows.h>
#include<stdio.h>
#include<iostream>

#pragma comment(lib,"ws2_32.lib")

struct DataPackage
{
    int age;
    char name[32];
};

int main()
{
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    //WinSocket启动
    WSAStartup(ver, &dat);

    //1、建立一个socket
    SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //AF_INET创建一个IPV4的套接字,SOCK_STREAM面向数据流的,IPPROTO_TCP TCP
    if (INVALID_SOCKET == _sock)
    {
        printf("ERROR:建立失败！\n");
    }
    //2.绑定
    sockaddr_in _sin = {};     //创建网络地址
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(4567); //Host to Network Short
    _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); // IP地址 
    if (bind(_sock, (sockaddr *)&_sin, sizeof(_sin)) == SOCKET_ERROR)
    {
        printf("ERROR:绑定失败！\n");
    }
    else
    {
        printf("TRUE:绑定成功！\n");
    }
    //3.监听网络端口
    if (listen(_sock, 5) == SOCKET_ERROR)//第二个参数为最大等待多少人可以同时连接
    {
        printf("ERROR:监听失败！\n");
    }
    else
    {
        printf("TRUE:监听成功！\n");
    }
    //4.等待接收客户端连接
    sockaddr_in clientAddr = {};
    int nAddrLen = sizeof(sockaddr_in);
    SOCKET _cSOCK = INVALID_SOCKET;
    
    _cSOCK = accept(_sock, (sockaddr *)&clientAddr, &nAddrLen);
    if (_cSOCK == INVALID_SOCKET)
    {
        printf("ERROR:无效客户端SOCKET！\n");
    }
    printf("新客户端加入：Socket=%d,IP = %s\n",(int)_cSOCK, inet_ntoa(clientAddr.sin_addr));//inet_ntoa(clientAddr.sin_addr)将接收到的IP地址转化为字符串
    char _recvBuff[128] = {};
    while (1)
    {
        //5.接收客户端新数据
        int nLen = recv(_cSOCK, _recvBuff, 128, 0);
        if (nLen <= 0)
        {
            printf("客户端已退出！任务结束！");
            break;
        }
        printf("收到命令：%s\n",_recvBuff);
        //6.请求处理
        if (0 == strcmp(_recvBuff, "getInfo"))
        {
            //7.向客户端发送一条数据
            DataPackage dp = { 80, "张国荣" };
            send(_cSOCK, (const char*)&dp, sizeof(DataPackage)+1, 0);
        }
        else{
            //7.向客户端发送一条数据
            char msgBuff[] = "???.\n";
            send(_cSOCK, msgBuff, strlen(msgBuff) + 1, 0);
        }
        
    }

    //8.关闭自身的socket
    closesocket(_sock);


    //WinSocket关闭
    WSACleanup();

    system("pause");
    return 0;
}

客户端：

#include<WinSock2.h>
#include<Windows.h>
#include<stdio.h>

struct DataPackage
{
    int age;
    char name[32];
};

#pragma comment(lib,"ws2_32.lib")

int main()
{
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    WSAStartup(ver, &dat);

    //1.建立一个socket
    SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (INVALID_SOCKET == _sock)
    {
        printf("ERROR:建立失败！\n");
    }
    //2.连接服务器
    sockaddr_in _sin = {};     //创建网络地址
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(4567); //Host to Network Short
    _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//inet_addr("127.0.0.1"); // IP地址 
    int ret = connect(_sock, (sockaddr *)&_sin, sizeof(sockaddr_in));
    if (SOCKET_ERROR == ret)
    {
        printf("ERROR:连接失败！\n");
    }
    else
    {
        printf("连接成功！\n");
    }

    while (true)
    {
        //3.输入请求命令
        char cmdBuff[128] = {};
        scanf("%s", cmdBuff);
        //4.处理请求命令
        if (0 == strcmp(cmdBuff, "exit"))
        {
            printf("收到exit命令，已退出1");
            break;
        }
        else{
            //5.向服务器发送请求命令
            send(_sock, cmdBuff, strlen(cmdBuff) + 1, 0);
        }
        //6.接收服务器信息
        char recvBuff[256] = {};
        int nlen = recv(_sock, recvBuff, 256, 0);
        if (nlen > 0)
        {
            DataPackage* dp = (DataPackage*)recvBuff;
            printf("接收到数据：年龄：%d,姓名：%s\n", dp->age,dp->name);
        }
    }

    
    //7.关闭套接字
    closesocket(_sock);

    //WinSocket启动
    WSAStartup(ver, &dat);



    //WinSocket关闭
    WSACleanup();
    printf("已退出!");
    getchar();
    return 0;
}