IOS 获取时间

    NSDate *date = [NSDate date];    NSCalendar *calendar = [NSCalendar currentCalendar];    NSDateComponents *comps;    //年月日    comps = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date];    NSInteger year = [comps year];    NSInteger rmonth = [comps month];    NSInteger day = [comps day];    //时分秒    comps = [calendar components:(NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:date];    NSInteger hour = [comps hour];    NSInteger minute = [comps minute];    NSInteger second = [comps second];    //星期几    comps = [calendar components:(NSWeekCalendarUnit | NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit) fromDate:date];    NSInteger week = [comps week];//今年的第几周    NSInteger weekdayOrdinal = [comps weekdayOrdinal];//这个月的第几周    NSInteger weekday = [comps weekday];//星期几（周日是“1”，周一是“2”）