2011-04-29 80 views
7

你知道如何知道两个NSDate是同一天吗?我要考虑到区域...如何知道两个NSDate是否在同一天

它可以很容易使用timeIntervalSinceDate:但周一23H58和周二00H01不在同一天...

NSDate和语言环境进行计算处理是不是很容易。

回答

18
NSCalendar *calendar = [NSCalendar currentCalendar]; 

NSDateComponents *componentsForFirstDate = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:firstDate]; 

NSDateComponents *componentsForSecondDate = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:secondDate]; 

if ([componentsForFirstDate year] == [componentsForSecondDate year]) 

我不知道是否会isEquals你想上什么NSDateComponents

+0

[NSCalendar currentCalendar]是十分缓慢的,所以如果可能的缓存它。 – 2011-04-29 15:38:00

+0

感谢您的回答。 “缓存”currentCal是什么意思?我把它放在一个单身人士? – iwalktheline 2011-04-29 16:08:33

+0

或者在NSCalendar上创建一个类别,将currentCalendar的结果存储为一个静态变量。 – 2011-04-29 19:49:12

7

使用NSCalendar和NSDateComponents为:

NSCalendar *cal = [NSCalendar currentCalendar]; 
NSDateComponents *comps1 = [cal components:(NSMonthCalendarUnit| NSYearCalendarUnit | NSDayCalendarUnit) 
             fromDate:date1]; 
NSDateComponents *comps2 = [cal components:(NSMonthCalendarUnit| NSYearCalendarUnit | NSDayCalendarUnit) 
             fromDate:date2]; 


BOOL sameDay = ([comps1 day] == [comps2 day] 
        && [comps1 month] == [comps2 month] 
        && [comps1 year] == [comps2 year]); 
5

与NSDateFormatter开始:

NSDateFormatter *_df = [[NSDateFormatter alloc] init]; 
_df.dateFormat = @"yyyy.MM.dd"; 
NSString *_d1 = [_df stringFromDate:_date1]; 
NSString *_d2 = [_df stringFromDate:_date2]; 
if ([_d1 isEqualToString:_d2] == YES) 
{ 
    // d1 and d2 is on same day/month/year 
} 
[_df release]; 
0

设置的timeZone如果日期是不是系统区域设置。

NSCalendar *calendar = [NSCalendar currentCalendar]; 
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:self.cityData.timeZone]; 
[calendar setTimeZone:timeZone]; 
NSDateComponents *componentsForFirstDate = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:weatherDataDate]; 
NSDateComponents *componentsForSecondDate = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:yesterday];    
if ([componentsForFirstDate day] == [componentsForSecondDate day]) { 
    // TODO: 
} 
6

斯威夫特:

func isSameDays(date1:NSDate, _ date2:NSDate) -> Bool { 
    let calendar = NSCalendar.currentCalendar() 
    var comps1 = calendar.components([NSCalendarUnit.Month , NSCalendarUnit.Year , NSCalendarUnit.Day], fromDate:date1) 
    var comps2 = calendar.components([NSCalendarUnit.Month , NSCalendarUnit.Year , NSCalendarUnit.Day], fromDate:date2) 

    return (comps1.day == comps2.day) && (comps1.month == comps2.month) && (comps1.year == comps2.year) 
} 
1

如果您的应用程序将会在OS X 10.9+或iOS上运行8+只有,你可以使用NSCalender新的API。

/* 
    This API compares the given dates down to the given unit, reporting them equal if they are the same in the given unit and all larger units. 
*/ 
- (BOOL)isDate:(NSDate *)date1 equalToDate:(NSDate *)date2 toUnitGranularity:(NSCalendarUnit)unit NS_AVAILABLE(10_9, 8_0); 

还有很多方便的API。但是,苹果并没有在他们的文档中提到它们。无论如何,这些API是公开的,您可以使用它们。

10

由于iOS 8的这个很简单:

let isSameDay = NSCalendar.currentCalendar().isDate(date1, inSameDayAsDate: date2) 

并且变得稍微简单但与夫特3

let isSameDay = Calendar.current.isDate(date1, inSameDayAs: date2) 
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