SYSTEMTIME与time_t之间的转换

time_t systemtime_to_time_t(const SYSTEMTIME& st)
{
	struct tm gm = {st.wSecond, st.wMinute, st.wHour, st.wDay, st.wMonth-1, st.wYear-1900, st.wDayOfWeek, 0, 0};
	return mktime(&gm);
}

SYSTEMTIME time_t_to_systemtime(time_t t)
{
	tm temptm = *localtime(&t);
	SYSTEMTIME st = {1900 + temptm.tm_year, 
		1 + temptm.tm_mon, 
		temptm.tm_wday, 
		temptm.tm_mday, 
		temptm.tm_hour, 
		temptm.tm_min, 
		temptm.tm_sec, 
		0};
	return st;
}