Question

我有一个带有nextCheck（NSDate），lastName（NSString）和firstName（NSString）键的数组控制器。我已经为数组设置了排序描述符。正如您在下面看到的，我首先按nextCheck排序，然后是lastName，然后是firstName。此出现不起作用，因为NSDate不仅由日期组件组成，还由时间组件组成。是否有一种简单的方法只按日期组件排序？

[_arrayCurrentVisits setSortDescriptors:[NSArray arrayWithObjects:[NSSortDescriptor sortDescriptorWithKey:@"nextVisit" ascending:YES selector:@selector(compare:)],[NSSortDescriptor sortDescriptorWithKey:@"lastName" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)], [NSSortDescriptor sortDescriptorWithKey:@"firstName" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)], nil]];

Answer 1

最简单的解决方案是add a method called nextVisitDate将nextVisit“截断”的值返回到午夜，然后按nextVisitDate排序。

[_arrayCurrentVisits setSortDescriptors:[ //                           vvv HERE vvv
    NSArray arrayWithObjects:[NSSortDescriptor sortDescriptorWithKey:@"nextVisitDate"  ascending:YES selector:@selector(compare:)]
,   [NSSortDescriptor sortDescriptorWithKey:@"lastName" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)]
,   [NSSortDescriptor sortDescriptorWithKey:@"firstName" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)]
,   nil]];

Answer 2

我做的是，当我创建日期时，我只使用日期的日期组件：

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *comps = [calendar components:(NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit) 
                                          fromDate:[NSDate date]];
NSDate *currentDate = [calendar dateFromComponents:comps];

排序NSDate而不考虑一天中的时间 - 只是日期

2 个答案: