两个NSDate对象之间的天数

Question

我正在尝试比较两天的NSDate对象,我在第一次使用NSDateComponents来计算我的两个日期对象之间的差异,但它工作正常.

    NSString *dateStr =@"2012-11-05 15:00:00";
    NSDate *date = [dateFormat dateFromString:dateStr];
    NSDateComponents *datesDiff = [calendar components: NSDayCalendarUnit
                                              fromDate: date
                                                toDate: [NSDate date]
                                               options: 0];

这不能解决我的问题.实际上,当date1 = 2012-11-05 23:00:00和date2 = 2012-11-06 10:00:00时,两个日期之间的差异是0天和11小时.我正在寻找能让我发现日期变化的东西,换句话说,当date1 = 2012-11-05 23:00:00和date2 = 2012-11-06 00:01:00时,有一天的差异.

如果有人知道解决方案,我会欢迎他的建议.提前致谢

Answer 1

我想你正在寻找这个(来自日期和时间编程指南):

清单13两个日期之间的天数,作为两者之间的中间数

@implementation NSCalendar (MySpecialCalculations)

-(NSInteger)daysWithinEraFromDate:(NSDate *) startDate toDate:(NSDate *) endDate
{
     NSInteger startDay=[self ordinalityOfUnit:NSDayCalendarUnit
          inUnit: NSEraCalendarUnit forDate:startDate];
     NSInteger endDay=[self ordinalityOfUnit:NSDayCalendarUnit
          inUnit: NSEraCalendarUnit forDate:endDate];
     return endDay-startDay;
}
@end

编辑:Swift版本:

extension NSCalendar {
    func daysWithinEraFromDate(startDate: NSDate, endDate: NSDate) -> Int {
        let startDay = self.ordinalityOfUnit(.Day, inUnit: NSCalendarUnit.Era, forDate: startDate)
        let endDay = self.ordinalityOfUnit(.Day, inUnit: NSCalendarUnit.Era, forDate: endDate)
        return endDay - startDay
    }
}

Answer 2

NSString *start = @"2010-09-01";
NSString *end = @"2010-12-01";

NSDateFormatter *f = [[NSDateFormatter alloc] init];
[f setDateFormat:@"yyyy-MM-dd"];
NSDate *startDate = [f dateFromString:start];
NSDate *endDate = [f dateFromString:end];
[f release];

NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorianCalendar components:NSDayCalendarUnit
                                                    fromDate:startDate
                                                      toDate:endDate
                                                     options:0];
[gregorianCalendar release];

组件现在有所不同.

NSLog(@"%ld", [components day]);