isBefore method
这指示Day对象是否在另一个提供的date-time之前。
Implementation
bool isBefore(Object date, [DayUnits unit = DayUnits.ms]) {
DayDart d = DayDart(date);
bool valid = isBeforeMillisecond(d);
switch (unit) {
case DayUnits.y:
valid = isBeforeYear(d);
break;
case DayUnits.M:
valid = isBeforeMonth(d);
break;
case DayUnits.D:
valid = isBeforeDay(d);
break;
case DayUnits.h:
valid = isBeforeHour(d);
break;
case DayUnits.m:
valid = isBeforeMinute(d);
break;
case DayUnits.s:
valid = isBeforeSecond(d);
break;
case DayUnits.ms:
valid = isBeforeMillisecond(d);
break;
}
return valid;
}