ios - UIDatePicker 最小/最大日期

Question

我创建了一个 UIDatePicker 以便用户可以选择他们的生日，并且我尝试设置允许的最小和最大日期。但是，像我在下面所做的那样设置最小/最大日期只会使超出范围的日期变灰，但您仍然可以滚动到它们。如何防止日期选择器滚动到这些日期而不是仅仅将它们灰显？

NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:1];
[comps setMonth:1];
[comps setYear:1914];
NSDate *minimumDate = [[NSCalendar currentCalendar] dateFromComponents:comps];

NSDateComponents *compsMax = [[NSDateComponents alloc] init];
[compsMax setDay:31];
[compsMax setMonth:12];
[compsMax setYear:2013];
NSDate *maximumDate = [[NSCalendar currentCalendar] dateFromComponents:compsMax];

birthdayPicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(220, 150, 500, 10)];
[birthdayPicker setDatePickerMode:UIDatePickerModeDate];
[birthdayPicker setMinimumDate:minimumDate];
[birthdayPicker setMaximumDate:maximumDate];
[birthdayPicker reloadInputViews];
[self addSubview:birthdayPicker];

Answer 1

我承认，它不是最好的，但试一试，也许它可以改进:

在viewDidLoad中

[birthdayPicker addTarget:self
                   action:@selector(pickerValueChanged:)
         forControlEvents:UIControlEventValueChanged];

代码中的其他地方

- (IBAction)pickerValueChanged:(id)sender {
    dispatch_async(dispatch_get_main_queue(), ^{
        UIDatePicker *datePicker = (UIDatePicker *)sender;
        if ([datePicker.date compare:datePicker.maximumDate] == NSOrderedDescending) {
            datePicker.date = datePicker.maximumDate;
        }
        else if ([datePicker.date compare:datePicker.minimumDate] == NSOrderedAscending) {
            datePicker.date = datePicker.minimumDate;
        }

    });
}