FormatMessage错误消息处理函数

LPTSTR GetLastErrMsg()
{
 LPTSTR lpTStr;
 DWORD dwErr=GetLastError();
 FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
   NULL,
   dwErr,
   MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
   (LPTSTR)&lpTStr,
   0x100,
   NULL);
 return lpTStr;
}