检查NSDate是在本周还是下周
有一种方法可以检查NSDate是本周还是下周？
我知道今天是：
[NSDate date] 然后我该怎么办？
使用NSDateComponents，如下所示：
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDate *today = [NSDate date]; NSDateComponents *todaysComponents = [gregorian components:NSWeekCalendarUnit fromDate:date]; NSUInteger todaysWeek = [todaysComponents week]; NSDate *anotherDate = [NSDate date]; NSDateComponents *otherComponents = [gregorian components:NSWeekCalendarUnit fromDate:anotherDate]; NSUInteger anotherWeek = [otherComponents week]; if(todaysWeek==anotherWeek){ NSLog(@"another date is this week"); }else if(todaysWeek+1==anotherWeek){ NSLog(@"another date is next week") }
您还可以使用月份或年份等其他组件来完全确定。
注意： 不要使用timeIntervals。 通过使用NSDateComponents，您可以忽略小时，分钟和秒。 我想你想要那个。
将2个日期传递给此方法：
- (BOOL) isSameWeekAsDate: (NSDate *) aDate andDate:(NSDate *) bDate { NSDateComponents *components1 = [[NSCalendar currentCalendar] components:(NSYearCalendarUnit| NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit) fromDate:aDate]; NSDateComponents *components2 = [[NSCalendar currentCalendar] components:(NSYearCalendarUnit| NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit) fromDate:bDate]; if ([components1 week] != [components2 week]) return NO; //return (abs([self timeIntervalSinceDate:aDate]) < 604800); // ops, forgot to change "self" with parameter "bDate": return (abs([bDate timeIntervalSinceDate:aDate]) < 604800); }
编辑：用不同年份的2个日期来称呼它：
[components setDay:31]; [components setMonth:12]; [components setYear:2010]; NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDate *date1 = [gregorian dateFromComponents:components]; // second date (SATURDAY -of the same week, other year...) [components setDay:1]; [components setMonth:1]; [components setYear:2011]; NSDate *date2 = [gregorian dateFromComponents:components]; if ([self isSameWeekAsDate:date1 andDate:date2]) { NSLog(@"Same Week!"); }else{ NSLog(@"OTHER WEEK!"); }
我正在添加我的解决方案（作为NSDate类别实现 ），它不使用在iOS7，iOS8中弃用的周
- (NSDate *)firstDateOfWeek { NSCalendar *calendar = [NSCalendar currentCalendar]; NSDate *startOfWeek; [calendar rangeOfUnit:NSCalendarUnitWeekOfYear startDate:&startOfWeek interval:NULL forDate:self]; return startOfWeek; } - (BOOL)isSameWeekWithDate:(NSDate *)date { if (ABS(self.timeIntervalSince1970 - date.timeIntervalSince1970) > (7 * 24 * 60 * 60)) { return NO; } return ([[self firstDateOfWeek] timeIntervalSince1970] == [[date firstDateOfWeek] timeIntervalSince1970]); } - (BOOL)isThisWeek { return [self isSameWeekWithDate:[NSDate new]]; }
NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:NSWeekCalendarUnit fromDate:yourDate]; NSInteger week = [components week]; // here your have a Integer with the weeknr of yourDate components = [cal components:NSWeekCalendarUnit fromDate:[NSDate date]]; weekToday = [components week]; // here your have a Integer with the weeknr of today
其余的你应该能够做到。 当涉及到一年的最后一周时，它可能会得到另一个脑力劳动。
明确？
注意：这使用星期日 – 星期六概念周计算“周”的想法。
要计算一周中的当前日期，请使用以下内容：
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *weekdayComponents =[gregorian components:NSWeekdayCalendarUnit fromDate:dateOfInterest]; NSInteger weekday = [weekdayComponents weekday]; // weekday 1 = Sunday for Gregorian calendar [gregorian release];
剩下的应该是微不足道的。 从NSDate获取当前日期和日期。 使用日期和日期查找开始日期和结束日期（如果今天是星期一，那么date - 1 day是一周的第一天等）。 弄清楚日期在哪一周。
对于iOS 7及更高版本，您必须使用NSCalendarUnitWeekOfYear替换NSCalendarUnitWeekOfYear
- (NSInteger)thisW:(NSDate *)date { NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *todaysComponents = [gregorian components:NSCalendarUnitWeekOfYear fromDate:[NSDate date]]; NSUInteger todaysWeek = [todaysComponents weekOfYear]; NSDateComponents *otherComponents = [gregorian components:NSCalendarUnitWeekOfYear 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; } }
忘记日期组件，你必须调整很多东西（检查它是否是一年的最后一周，检查星期日是否是一周的开始……）并且容易出错和意大利面条代码。
这解决了您的问题，并扩展到检测“上周”，“前几周”，“本周”，“下周”和“后几周”
-(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; } } }