完美实现 Windows 下网络通信

编译环境：DEV C++

配置编译器

Windows 下 实现 Socket 编译需要 ws2_32.lib 这个库的支撑，所以我们编译前应该配置下编译器，具体配置步骤如下：

Tools -> Compiler Options

加入 -l 链接，如图所示：

实现的功能

服务器端与客户端可以互相自由给对方发送消息，无需在意接收与发送的顺序（利用线程实现）！可以实现加法运算。如需其它的功能，可以自行补充，如：实现四则运算、文件传输等。

服务器程序

/*
    Name: TCP Server 
    Copyright: -lws2_32
    Author: Lance#
    Date: 18/05/18
    Description: TCP Server 
*/

#include <stdio.h>    
#include <winsock2.h> 
#include <windows.h>
#include <string.h>

#define PORT        8080  
#define BUFSIZE     1024

/* 客户端Socket与发送缓冲 */
SOCKET client;
unsigned char SendBuf[BUFSIZE+1];

enum{
    NoConnection,
    Connected,
}LinkStatus;

/* 客户端连接状态监控线程 */
DWORD WINAPI print_message(LPVOID arg)
{
    while(1){
        if(!LinkStatus){
            printf("    等待客户端连接 .... \r\n");
            sleep(1);
        }
    }
}

/* 服务器发送消息线程 */
DWORD WINAPI send_message(LPVOID arg)
{   
    while(1){
        memset(SendBuf, 0, 1024); 
        fgets(SendBuf, 1024, stdin);
        send(client, SendBuf, 1024, 0);
    }
} 

int main(int argc, char* argv[])
{
    WSADATA wsaData;
    struct sockaddr_in sin_addr;
    struct sockaddr_in remoteAddr;
    unsigned char recvData[BUFSIZE+1];
    int nAddrlen = sizeof(remoteAddr);
    
    unsigned int num_l, num_r;
    unsigned char sum_buf[100] = {0};
    
    /* 线程标识 */
    HANDLE pthread;
    
    /* 启动 WSA */
    WORD sockVersion = MAKEWORD(2, 2);

    if (WSAStartup(sockVersion, &wsaData)){
        perror("WSA boot failed!");
        return -1;
    }

    /* 创建服务端套接字 */
    SOCKET server = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (server == INVALID_SOCKET){
        perror("socket error!");
        return -1;
    }

    /* 配置 sin_addr */
    sin_addr.sin_family = AF_INET;
    sin_addr.sin_port = htons(PORT);
    /* 可监听任意的地址 */
    sin_addr.sin_addr.S_un.S_addr = INADDR_ANY; 
    /* 监听指定的地址 */
//    sin_addr.sin_addr.S_un.S_addr = inet_addr("192.168.1.149"); 
    
    /* 绑定 */
    if (bind(server, (LPSOCKADDR)&sin_addr, sizeof(sin_addr)) == SOCKET_ERROR){
        perror("bind error!");
        return -1;
    }

    /* 监听 */
    if (listen(server, 100) == SOCKET_ERROR){
        perror("listen error!");
        return -1;
    }
    
    puts("服务器成功启动"); 
    
    /* 创建状态线程 */
    CreateThread(NULL,0,print_message,NULL,0,NULL);
    /* 创建消息线程 */
    pthread = CreateThread(NULL,0,send_message,NULL,0,NULL);

    while (1)
    {   
        LinkStatus = NoConnection;
        client = accept(server, (SOCKADDR *)&remoteAddr, &nAddrlen);
        LinkStatus = Connected;
        
        if (client == INVALID_SOCKET)
        {
            perror("accept error!");
            continue;
        }
        
        printf("客户端：%s 已连接\r\n", inet_ntoa(remoteAddr.sin_addr));

        while(1){

            /* 数据接收 */
            memset(recvData, 0, sizeof(recvData));
            int ret = recv(client, recvData, 1024, 0);
            if (ret > 0){
                printf("Recv:   %s", recvData);
                /* 实现加法运算，客户端发来  "%d + %d =" 形式的数据后，将结果返回至客户端 */
                if(sscanf(recvData, "%d + %d =", &num_l, &num_r) == 2){
                    sprintf(sum_buf, "%d + %d ,sum is %d", num_l, num_r, num_l + num_r);
                    send(client, sum_buf, sizeof(sum_buf), 0);
                    memset(sum_buf, 0, sizeof(sum_buf));
                }
            }else
                /* 客户端异常则断开当前连接 */
                goto Reconnect;
                
            /* 客户端要求退出的话则断开当前连接 */
            if(!strncmp(recvData, "quit", 4))
                goto Reconnect;
        }
        
    Reconnect:
        closesocket(client);
        puts("*** 客户端已断开");
    }

    /* 关闭服务器套接字 */
    closesocket(server); 
    WSACleanup();
    
    return 0;
}

客户端程序

/*
    Name: TCP Client 
    Copyright: -lws2_32
    Author: Lance#
    Date: 18/05/18
    Description: TCP Client
*/

#include <stdio.h>  
#include <winsock2.h>  
#include <Windows.h>  
#include <string.h>
  
#define PORT        8080  
#define BUFSIZE     1024

unsigned char recvData[BUFSIZE+1] = {0};  

/* 线程标识 */
HANDLE pthread;

DWORD WINAPI recv_message(LPVOID arg)
{
    int res;
    
    while(1){
        memset(recvData, 0, 1024); 
        res = recv((SOCKET)arg, recvData, 1024, 0);
        if(res > 0)
            printf("Recv:   %s", recvData);
        else{
            printf("*** 服务器已退出(回车退出程序)");
            return 0;
        } 
    }
}
  
int main(int argc, char * argv[])  
{  
    unsigned char SendBuf[BUFSIZE+1] = {0};  
    WSADATA wsaData;
    SOCKADDR_IN addrServ;  
    
    if(argc != 2){
        puts("argc error");
        puts("Usage: <client.exe> <ip addr>");
        return -1;
    }

    /* 启动 WSA */
    WORD sockVersion = MAKEWORD(2, 2);

    if (WSAStartup(sockVersion, &wsaData)){
        perror("WSA boot failed!");
        return -1;
    }
    
    /* 创建 socket */
    SOCKET client = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  
    if (client == INVALID_SOCKET){  
        perror("socket failed");  
        return -1;  
    }  
    
    /* 配置 socket */
    addrServ.sin_family = AF_INET;  
    addrServ.sin_port = htons(PORT);  
    /* 配置服务器 IP */
    addrServ.sin_addr.S_un.S_addr = inet_addr(argv[1]);  
      
    /* 连接至服务器 */
    int ret = connect(client,(SOCKADDR*)&addrServ,sizeof(SOCKADDR));
    if (SOCKET_ERROR == ret){  
        perror("socket connect failed");  
        closesocket(client);  
        WSACleanup();  
        return -1;  
    }  
    
    /* 创建工作线程 */
    pthread = CreateThread(NULL,0 ,recv_message,(LPVOID)client,0,NULL);
    
    puts("客户端成功启动，输入'quit'关闭客户端"); 
    
    while(1)
    {
        memset(SendBuf,0,sizeof(SendBuf));  
        
        fgets(SendBuf, 1024, stdin);
        
        ret = send(client, SendBuf, 1024, 0);  
        if (SOCKET_ERROR == ret){  
            closesocket(client);  
            exit(0);
        } 
        
        /* 客户端退出 */
        if(!strncmp(SendBuf, "quit", 4))
            goto Disconnect;
    }

Disconnect:  
    closesocket(client);  
    WSACleanup();  
    
    return 0;  
}  

运行结果演示

打开 CMD，进入可执行文件所在目录

执行 server.exe 运行服务器;
启动另一个 CMD，执行 client.exe 127.0.0.1 运行客户端。

双方可进行通信，效果如图：