UITextField 不会在 UIDatePicker 动作事件上触发动作事件

Question

我有一个更新我的文本字段的 datePicker。一旦 textField 数据发生更改，就应该执行操作（例如验证数据）。问题是datePicker更新textField后，textField不执行任何动作，不管我在textField上使用什么动作事件，比如.ValueChanged。我无法弄清楚问题是什么。不过我注意到，如果我要在 textField 中输入内容，则操作事件会起作用。 这是我的代码：

class CustomTextField: UITextField, UITextFieldDelegate {

    var customDelegate : CustomTextFieldDelegate?

    enum type {
        case standard
        case date
    }

    var textFieldType : type = .standard {
        didSet{
            switch self.textFieldType {
            case .standard:
                break
            case .date:
                let datePicker = UIDatePicker.MMMddyyyy
                self.inputView = datePicker
                datePicker.addTarget(self, action: #selector(refreshOnDatePicker(_:)), for: .valueChanged)
                self.addTarget(self, action: #selector(checkFieldInput), for: .applicationReserved)
                break
            }
        }
    }


    @objc private func checkFieldInput(sender: CustomTextField){
        guard let fieldInput = self.text else { return }
        switch sender.textFieldType {
            case .standard:
                break
            case .date:
                customDelegate?.isTextFieldVerified = !fieldInput.isEmpty
            break
        }
    }

    @objc private func refreshOnDatePicker(_ selector: UIDatePicker){
        self.text = selector.date.formattedMMMMddyyyy
    }
}


fileprivate extension UIDatePicker {
    class var MMMddyyyy : UIDatePicker {
        let currentDate: NSDate = NSDate()



    let calendar: NSCalendar = NSCalendar(calendarIdentifier: NSCalendar.Identifier.gregorian)!
    calendar.timeZone = NSTimeZone(name: "UTC")! as TimeZone

    let components: NSDateComponents = NSDateComponents()
    components.calendar = calendar as Calendar
    components.year = -100

    let minDate: NSDate = calendar.date(byAdding: components as DateComponents, to: currentDate as Date, options: NSCalendar.Options(rawValue: 0))! as NSDate

    let dp = UIDatePicker()
    dp.datePickerMode = .date
    dp.minimumDate = minDate as Date
    dp.maximumDate = currentDate as Date
    dp.backgroundColor = UIColor.white
    return dp
   }
}

fileprivate extension Date {
    /// date formatted type "MMMM dd, yyyy"
    var formattedMMMMddyyyy: String {
        let formatter = DateFormatter()
        formatter.dateFormat = "MMMM dd, yyyy"
        return  formatter.string(from: self)
    }
}

Answer 1

试试这个

 @objc private func refreshOnDatePicker(_ selector: UIDatePicker){
    self.text = selector.date.formattedMMMMddyyyy
    self.checkFieldInput(sender:self)
}