hostent* phost;
CString csMyip;
                  in_addr addr;
ZeroMemory(buf,sizeof(buf));
gethostname(buf,sizeof(buf));
phost=gethostbyname(buf);
addr.S_un.S_addr=**((DWORD**)phost->h_addr_list);
csMyip=inet_ntoa(addr);
得到计算机名也可以用GetComputerName