NSCalendar [_NSCopyOnWriteCalendarWrapper组件:fromDate:]:错误

Question

在tableviewcontroller中,我有这个代码来获取从0到6的天数,其中首先是当前dayNumber的顺序.

self.dayOrder=[NSMutableArray new];

NSCalendar *cal=[NSCalendar currentCalendar];

NSInteger dayNumber = [cal component:NSCalendarUnitWeekday fromDate:[NSDate date]]-1; // Sunday gives 0,

for (int i=0;i<7;i++) {
    [self.dayOrder addObject:[NSNumber numberWithInteger:dayNumber]];
    dayNumber=(dayNumber+1)%7;
}

当我移动到此视图控制器时,我收到此错误 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_NSCopyOnWriteCalendarWrapper component:fromDate:]: unrecognized selector sent to instance 0x15e4b850'

当我添加一个ALL Exceptions断点时,此行发生错误

 NSInteger dayNumber = [cal component:NSCalendarUnitWeekday fromDate:[NSDate date]]-1; // Sunday gives 0,

它似乎正在我的iPhone 6上运行,但它在iOS 8上,而不是iOS7上的iPone 4,5c.

不知道为什么会这样,为什么会有任何帮助将不胜感激.

谢谢您的帮助!!!

Answer 1

该component:fromDate:方法已添加到NSCalendariOS 8.0中.

如果您需要支持较旧的iOS版本,请使用旧components:fromDate:方法并从结果中提取所需的值NSDateComponents.

NSDateComponents *components = [cal components:NSCalendarUnitWeekday fromDate:[NSDate date]];
NSInteger weekday = [components weekday] - 1;