SYSTEMTIME与time_t相互转换

void TimetToSystemTime( time_t t, LPSYSTEMTIME pst )
{
   FILETIME ft;
   LONGLONG ll = Int32x32To64(t, 10000000) + 116444736000000000;
   ft.dwLowDateTime = (DWORD) ll;
   ft.dwHighDateTime = (DWORD)(ll >> 32);

   FileTimeToSystemTime( &ft, pst );
}

void SystemTimeToTimet( SYSTEMTIME st, time_t *pt )
{
   FILETIME ft;
   SystemTimeToFileTime( &st, &ft );

   LONGLONG ll;

   ULARGE_INTEGER ui;
   ui.LowPart = ft.dwLowDateTime;
   ui.HighPart = ft.dwHighDateTime;

   ll = (ft.dwHighDateTime << 32) + ft.dwLowDateTime;

   *pt = (DWORD)((LONGLONG)(ui.QuadPart - 116444736000000000) / 10000000);
}