检查 NSDate 是否在下周

Question

我尝试了以下代码，但我没有得到 date 在下周的条件。我怎么知道函数中的参数 date 会在下周下降？始终遵循代码 returns 1.

- (NSInteger)thisW:(NSDate *)date
{
    NSCalendar *gregorian = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *todaysComponents =
    [gregorian components:NSYearCalendarUnit fromDate:[NSDate date]];

    NSUInteger todaysWeek = [todaysComponents weekOfYear];


    NSDateComponents *otherComponents =
    [gregorian components:NSYearCalendarUnit fromDate:date];

    NSUInteger datesWeek = [otherComponents weekOfYear];
    //NSLog(@"Date %@",date);
    if(todaysWeek==datesWeek){
        //NSLog(@"Date is in this week");
        return 1;
    }else if(todaysWeek+1==datesWeek){
        //NSLog(@"Date is in next week");
        return 2;
    } else {
        return 0;
    }

}

Answer 1

提取日期成分时需要传入NSCalendarUnitWeekOfYear：

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *todaysComponents = [gregorian components:NSCalendarUnitWeekOfYear fromDate:[NSDate date]];
NSUInteger todaysWeek = [todaysComponents weekOfYear];
NSDateComponents *otherComponents = [gregorian NSCalendarUnitWeekOfYear fromDate:date];
NSUInteger datesWeek = [otherComponents weekOfYear];

Answer 2

使用 datecomponents 进行周计算会在日期接近年底时给您带来问题，即 "The first week of the year is designated to be the week containing the first Thursday of the year.(ISO 8601)"

我发现以一定的粒度比较日期更容易，在这种情况下是每周一次（以下代码检测一个日期是否超过过去一周、上周、本周、下周或未来更长时间)

-(EventWeekRange)numberOfWeeksFromTodayToEvent:(NSDate *)eventDate {
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSComparisonResult comparison = [calendar compareDate:[NSDate date] toDate:eventDate toUnitGranularity:NSCalendarUnitWeekOfYear];
    if (comparison == NSOrderedSame) {
        return RangeThisWeek;
    } else if (comparison == NSOrderedAscending) { // The event date is in the future
        // Advance today's date one week to check if this new date is in the same week as the event
        NSDate *todaysNextWeek = [[NSDate date]dateByAddingTimeInterval:60*60*24*7];
        if ([calendar compareDate:todaysNextWeek toDate:eventDate toUnitGranularity:NSCalendarUnitWeekOfYear] == NSOrderedSame) {
            return RangeNextWeek;
        } else {
            return RangeLater;
        }
    } else { // The event date is in the past
        // Advance the event's date one week to check if this new date is in the same week as today
        NSDate *eventsNextWeek = [eventDate dateByAddingTimeInterval:60*60*24*7];
        if ([calendar compareDate:eventsNextWeek toDate:[NSDate date] toUnitGranularity:NSCalendarUnitWeekOfYear] == NSOrderedSame) {
            return RangeLastWeek;
        } else {
            return RangeEarlier;
        }
    }
}

检查 NSDate 是否在下周

Check if NSDate is in next week

objective-c

nsdate