将 NSDate 更改为该周的星期五

Change NSDate to Friday of that Week

目前我有下面的代码可以将我的天数增加到下一个星期五,但是我需要的是获取本周的星期五。例如,如果是上周日,03/01。我希望我的回复是在上周五 (02/28) 而不是周五 (03/06)。

我已经检查了其他答案,但对如何实现一个干净的方法来完成这个感到困惑。

+ (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;
}

尝试使用 setWeekday 设置特定的一天

-(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];
}