xcode 如何在 iOS 的 UIDatePicker 中阻止天数
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How to block days in UIDatePicker for iOS
提问by Pach
I'm using a Date picker on my IOS app, and I want to know if is possible to block some days. For example, I need to block all mondays from a year, is this possible?
我在我的 IOS 应用程序上使用日期选择器，我想知道是否可以阻止几天。例如，我需要阻止一年中的所有星期一，这可能吗？
Thanks.
谢谢。
回答by E. Lüders
The only thing you can do is add a custom UIPickerView as described in the comments or implement a method that is called for the event UIControlEventValueChangedas described here
你唯一可以做的事情是在评论描述添加自定义UIPickerView或实现一个被称为该事件的方法UIControlEventValueChanged描述在这里
then check the new value for a valid weekday. you can get the weekday with:
然后检查有效工作日的新值。您可以通过以下方式获得工作日：
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDateComponents* components = [calendar components:NSWeekdayCalendarUnit fromDate:[NSDate date]];
return [components weekday]; // 1 = Sunday, 2 = Monday, ...
There is no way to hide some days in the scrollwheel.
无法在滚轮中隐藏某些日子。
回答by iCappsCVA
Here is the Swift 4answer to this question (original answer by Nicholas Harlen):
这是这个问题的Swift 4答案（Nicholas Harlen 的原始答案）：
let datePicker: UIDatePicker = UIDatePicker(frame: .zero)
datePicker.datePickerMode = .date
datePicker.addTarget(self, action: #selector(datePickerValueChanged(_:)), for: .valueChanged)
@objc func datePickerValueChanged(_ sender: UIDatePicker) {
let calender: Calendar = Calendar(identifier: .gregorian)
let weekday = calender.component(.weekday, from: sender.date)
//sunday
if weekday == 1 {
datePicker.setDate(Date(timeInterval: 60*60*24*1, since: sender.date), animated: true)
} else if weekday == 7 {
datePicker.setDate(Date(timeInterval: 60*60*24*(-1), since: sender.date), animated: true)
}
}
回答by Nicholas Harlen
I had to do something similar and couldn't find a way of removing dates. However what I ended up doing was if an invalid date is selected it would bounce away to the nearest day that was valid, similar to how the control handles if you set a minimum date and try and choose a date before that.
我不得不做类似的事情，但找不到删除日期的方法。但是，我最终做的是，如果选择了无效日期，它会反弹到最近的有效日期，类似于如果您设置最小日期并尝试选择之前的日期，控件的处理方式。
-(void)init
{
datePicker = [[UIDatePicker alloc] initWithFrame:CGRectZero];
[datePicker setDatePickerMode:UIDatePickerModeDate];
[datePicker setMinimumDate: [NSDate date]];
[datePicker addTarget:self action:@selector(onDatePickerValueChanged:) forControlEvents:UIControlEventValueChanged];
}
-(void)onDatePickerValueChanged:(UIDatePicker *)picker
{
// Work out which day of the week is currently selected.
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSDateComponents *comps = [gregorian components:NSWeekdayCalendarUnit fromDate:picker.date];
int weekday = [comps weekday];
// Bounce Sundays (weekday=1) forward a day
if (weekday == 1)
{
[datePicker setDate:[NSDate dateWithTimeInterval:60*60*24*1 sinceDate:picker.date] animated: true];
}
// Bounce Saturdays (weekday=7) back a day
else if (weekday == 7)
{
[datePicker setDate:[NSDate dateWithTimeInterval:60*60*24*-1 sinceDate:picker.date] animated: true];
}
}
