VC++ UDP网络控制台程序

 采用的是VC2008,控制台应用程序，使用UDP编写。

1、服务端代码

//UDPServer.cpp

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

#define SERVERPORT 6000 //服务端口号  

#pragma comment(lib, "WS2_32.lib")

int main(int argc, char *argv[])
{
    //加载套接字库
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;  

    wVersionRequested = MAKEWORD( 2, 2 );  

    err = WSAStartup( wVersionRequested, &wsaData );
    if ( err != 0 ) {
        /* Tell the user that we could not find a usable */
        /* WinSock DLL.                                  */
        return -1;
    }  

    /* Confirm that the WinSock DLL supports 2.2.*/
    /* Note that if the DLL supports versions greater    */
    /* than 2.2 in addition to 2.2, it will still return */
    /* 2.2 in wVersion since that is the version we      */
    /* requested.                                        */  

    if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
            /* Tell the user that we could not find a usable */
            /* WinSock DLL.                                  */
            WSACleanup( );
            return -1;
    }  

    /* The WinSock DLL is acceptable. Proceed. */
    //创建套接字
    SOCKET sockServer = socket(AF_INET, SOCK_DGRAM, 0);
    if (INVALID_SOCKET == sockServer)
    {
        printf("socket() called failed! The error code is: %d\n", WSAGetLastError());
        return -1;
    }
    else
    {
        printf("socket() called succesful!\n");
    }  

    //服务器端
    SOCKADDR_IN addrServer;
    addrServer.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
    addrServer.sin_family = AF_INET;
    addrServer.sin_port = htons(SERVERPORT);  

    //绑定套接字
    err = bind(sockServer, (SOCKADDR*)&addrServer, sizeof(SOCKADDR));
    if (SOCKET_ERROR == err)
    {
        printf("bind() called failed! The error code is: %d\n", WSAGetLastError());
        return -1;
    }
    else
    {
        printf("bind() called successful!\n");
    }  

    //等待并接收数据
    SOCKADDR_IN addrClient;//用于接收发送端的地址信息
    int len = sizeof(SOCKADDR);
    char recvBuf[100];
    recvfrom(sockServer, recvBuf, 100, 0, (SOCKADDR*)&addrClient, &len);
    //打印接收到的数据
    printf("receive data:%s from client [%s,%d]", recvBuf, inet_ntoa(addrClient.sin_addr), addrClient.sin_port);  

    //关闭套接字
    closesocket(sockServer);  

    //终止套接字库的使用
    WSACleanup();  

    return 0;
}  

2、客户端代码

//UDPClient.cpp

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

#define SERVERPORT 6000 //服务端口号  

#pragma comment(lib, "WS2_32.lib") 

int main(int argc, char *argv[])
{
    //加载套接字库
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;  

    wVersionRequested = MAKEWORD( 2, 2 );  

    err = WSAStartup( wVersionRequested, &wsaData );
    if ( err != 0 ) {
        /* Tell the user that we could not find a usable */
        /* WinSock DLL.                                  */
        return -1;
    }  

    /* Confirm that the WinSock DLL supports 2.2.*/
    /* Note that if the DLL supports versions greater    */
    /* than 2.2 in addition to 2.2, it will still return */
    /* 2.2 in wVersion since that is the version we      */
    /* requested.                                        */  

    if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
            /* Tell the user that we could not find a usable */
            /* WinSock DLL.                                  */
            WSACleanup( );
            return -1;
    }  

    //创建套接字
    SOCKET sockClient = socket(AF_INET, SOCK_DGRAM, 0);
    if (INVALID_SOCKET == sockClient)
    {
        printf("socket() called failed! The error code is: %d\n", WSAGetLastError());
        return -1;
    }
    else
    {
        printf("socket() called succesful!\n");
    }  

    SOCKADDR_IN addrServer;
    addrServer.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    addrServer.sin_family = AF_INET;
    addrServer.sin_port = htons(SERVERPORT);  

    //发送数据
    err = sendto(sockClient, "Hello", strlen("Hello")+1, 0, (SOCKADDR*)&addrServer, sizeof(SOCKADDR));
    if (SOCKET_ERROR == err)
    {
        printf("sendto() called failed! The error code is: %s\n", WSAGetLastError());
        return -1;
    }
    else
    {
        printf("sendto() called successful!\n");
    }  

    //关闭套接字
    closesocket(sockClient);  

    //终止套接字库的使用
    WSACleanup();  

    return 0;
} 

注意：上面两部分代码中的

#pragma comment(lib, "WS2_32.lib")

可以删除，而改为设置程序属性，具体如下步骤：

　server 和 client 都要"项目属性"--->"配置属性"----> "链接"----> "输入" --->"附加依赖项"中添加"ws2_32.lib"。

先启动服务端UDPServer程序，再启动客户端UDPClient程序，运行结果如下：

服务端UDPServer

客户端UDPClient

此时服务端UDPServer的结果会发生变化，会受到客户端发送过来的数据，如下图所示：

参考资料：

1、《VC++深入详解》 第14章网络编程 ，孙鑫主编

2、MSDN帮助文档

原文链接：VC++ UDP网络控制台程序