int SockSend(DataPack &dataPack, SOCKET &sock, char *sockBuf){
int bytesLeft=0, bytesSend=0;
int idx=0;

bytesLeft=sizeof(dataPack);

// ?DataPack?????sockBuf???
memcpy(sockBuf, &dataPack, sizeof(dataPack));

while(bytesLeft>0){
    memset(sockBuf, 0, sizeof(sockBuf));

    bytesSend=send(sock, &sockBuf[idx], bytesLeft, 0);
    cout<<"??send()??, bytesSend: "<<bytesSend<<endl;
    if(bytesSend==SOCKET_ERROR){
        cout<<"Error at send()."<<endl;
        cout<<"Error # "<<WSAGetLastError()<<" happened."<<endl; 
        return 1;
    }
    bytesLeft-=bytesSend;
    idx+=bytesSend;
}
cout<<"DataPack ???????"<<endl;
return 0;

}

This is the function I defined, which is used to send a user_defined structure DataPack. My code in test project is as follows:

char sendBuf[100000];
int res=SockSend(dataPack, sockConn, sendBuf);
if(res==1){
    cout<<"SockSend()???"<<endl;
}else{
    cout<<"SockSend()???"<<endl;
}

My code in my current project is: err=SockSend(dataPackSend, sockConn, sockBuf); if(err==1){ cout<<"SockSend()??"<<endl; exit(0); }else{ cout<<"??? "<<dataPackSend.packNum<<" ?DataPack(??)"<<endl; }

Can you tell me where does this function go wrong? I will be appreciated for you answer.