objective-c - 将 NSDate 更改为该周的星期五

Question

目前我有下面的代码来增加我的日子到下一个星期五，但是我需要的是获得本周的星期五。例如，如果是上周日，03/01。我希望我的回复是上周五（02/28）而不是周五（03/06）。

我已经检查了其他答案，但对如何实现一种干净的方式来实现这一点感到困惑。

+ (NSDate *)getLastFridayYearsMonthStartingDate:(NSDate *)date {

NSDateComponents *dateComponents = [[NSCalendar gregorianCalendar] components:NSYearCalendarUnit|NSCalendarUnitDay|NSCalendarUnitMonth|NSWeekdayCalendarUnit
                                                                     fromDate:date];

     // Set date to last year, +1 to account for previous business day
     [dateComponents setYear: -1];
     [dateComponents setDay:[dateComponents day]+1];


    // We always want the start date to be the friday of the given week, so we will increment the difference if not
    if ([dateComponents weekday] != 6) {
        NSInteger daysToFriday = (13 - [dateComponents weekday]) % 7;
        [dateComponents setDay:[dateComponents day]+daysToFriday];
    }

    NSDate *fridayDate = [[NSCalendar gregorianCalendar] dateFromComponents:dateComponents];

    return fridayDate;
}

Answer 1

尝试使用 setWeekday 设置特定日期

-(NSDate *) getFriday:(NSDate *)date {
    NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    [cal setTimeZone:[NSTimeZone systemTimeZone]];

    NSDateComponents *comp = [cal components:NSYearCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:date];


    [comp setWeekday:6];
    [comp setHour:0];
    [comp setMinute:0];
    [comp setSecond:0];
    return [cal dateFromComponents:comp];
}