用按钮编辑UIDatePicker？

Question

在我的应用程序中，我有下一周和上周按钮，但也有UIDatePicker。那么让我说按净周按钮，如何调整UIDatePicker中的日期增加7天？反过来7天也是如此。

谢谢！

Answer 1

使用dateByAddingTimeInterval:类的NSDate方法和setDate:animated:类的UIDatePicker方法来调整选择器的当前日期：

NSDate *currentDate = [datePicker date];

// Set the date 7 days earlier
NSDate *sevenDaysEarlier = [currentDate dateByAddingTimeInterval:-(60 * 60 * 24 * 7)];
[datePicker setDate:sevenDaysEarlier animated:YES];

// Set the date 7 days later
NSDate *sevenDaysLater = [currentDate dateByAddingTimeInterval:60 * 60 * 24 * 7];
[datePicker setDate:sevenDaysLater animated:YES];