所有NSDate数组一个星期
我想有一个函数，需要一个星期的数字作为input，并返回该特定星期所做的所有NSDate的数组。
像这样的东西：
-(NSArray*)allDatesInWeek:(int)weekNumber { NSDate *today = [NSDate date]; NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; [calendar setFirstWeekday:2]; NSDateComponents *todayComp = [calendar components:NSYearCalendarUnit fromDate:today]; int currentyear = todayComp.year; /* Calculate and return the date of weekNumber for current year */ }
这怎么能以简单的方式完成呢？
testing。
-(NSArray*)allDatesInWeek:(int)weekNumber { // determine weekday of first day of year: NSCalendar *greg = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *coms = [[NSDateComponents alloc] init]; comps.day = 1; NSDate *today = [NSDate date]; NSDate *tomorrow = [greg dateByAddingComponents:comps toDate:today]; const NSTimeInterval kDay = [tomorrow timeIntervalSinceDate:today]; comps = [greg components:NSYearCalendarUnit fromDate:[NSDate date]]; comps.day = 1; comps.month = 1; comps.hour = 12; NSDate *start = [greg dateFromComponents:comps]; comps = [greg components:NSWeekdayCalendarUnit fromDate:start]; if (weekNumber==1) { start = [start dateByAddingTimeInterval:-kDay*(comps.weekday-1)]; } else { start = [start dateByAddingTimeInterval: kDay*(8-comps.weekday+7*(weekNumber-2))]; } NSMutableArray *result = [NSMutableArray array]; for (int i = 0; i<7; i++) { [result addObject:[start dateByAddingTimeInterval:kDay*i]]; } return [NSArray arrayWithArray:result]; }
这假定星期的第一天是星期天，如NSDate API中所述。 如果需要调整。
这个解决scheme完全依赖于NSCalendar，而不对用户的日历做任何假设。
-(NSArray*)allDatesInWeekContainingDate:(NSDate*)referenceDate { NSCalendar *calendar = [NSCalendar currentCalendar]; NSInteger ordinalityOfInput = [calendar ordinalityOfUnit:NSWeekdayCalendarUnit inUnit:NSWeekCalendarUnit forDate:referenceDate]; NSDateComponents *componentsToAdd = [[NSDateComponents alloc] init]; componentsToAdd.day = -1 * (ordinalityOfInput - 1); NSDate *startDate = [calendar dateByAddingComponents:componentsToAdd toDate:referenceDate options:0]; NSInteger numDaysInWeek = [calendar maximumRangeOfUnit:NSWeekdayCalendarUnit].length; NSMutableArray *allDays = [NSMutableArray arrayWithCapacity:numDaysInWeek]; NSDateComponents *curDayOffset = [[NSDateComponents alloc] init]; for (int curDay=0; curDay < numDaysInWeek; curDay++) { curDayOffset.day = curDay; [allDays addObject:[calendar dateByAddingComponents:curDayOffset toDate:startDate options:0]]; } return allDays; }