SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0);

BOOL bBroadcast = TRUE; 
::setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&bBroadcast, sizeof(BOOL));

#include "InitSock.h" 
#include <stdio.h> 
 
VOID main() 
{ 
    CInitSock initSock; 
 
    SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0); 
    //設(shè)置廣播就是設(shè)置這個(gè)選項(xiàng) 
    BOOL bBroadcast = TRUE; 
    ::setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&bBroadcast, sizeof(BOOL)); 
 
    //設(shè)置廣播地址 
    SOCKADDR_IN bcast; 
    bcast.sin_family = AF_INET; 
    bcast.sin_port = htons(4567); 
    bcast.sin_addr.S_un.S_addr = INADDR_BROADCAST; //::inet_addr("255.255.255.255"); 
    printf("begin send the data:\r\n"); 
    char sz[] = "this is the broadcast data"; 
    while(TRUE) 
    { 
        ::sendto(s, sz, sizeof(sz), 0, (sockaddr*)&bcast, sizeof(bcast)); 
        ::Sleep(5000); 
    } 
}

#include "InitSock.h" 
#include <stdio.h> 
 
void main() 
{ 
    CInitSock initSock; 
 
    SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0); 
 
    SOCKADDR_IN sin;  
    sin.sin_family = AF_INET; 
    sin.sin_port = ::htons(4567); 
    sin.sin_addr.S_un.S_addr = INADDR_ANY; 
    if (::bind(s, (sockaddr*)&sin, sizeof(sin)) == SOCKET_ERROR) 
    { 
        printf("bind error"); 
        return; 
    } 
 
    printf("begin recv the broadcast data:\r\n"); 
    char sz[256] = {0}; 
    SOCKADDR_IN addrRemote; 
    int nLen = sizeof(SOCKADDR_IN); //這里必須設(shè)置成這個(gè)大小  
    while (TRUE) 
    { 
        int nRet = ::recvfrom(s, sz, sizeof(sz), 0, (sockaddr*)&addrRemote, &nLen); 
        if (nRet > 0) 
        { 
            sz[nRet] = '\0'; 
            printf(sz); 
        } 
 
    } 
}