Swift: using UIDatePicker as UITextField inputView not updating

问题

I have a textfield and when it is selected a datepicker pops up instead of a keyboard, but it only updates with todays date the first time. The user changes the date, but the textfield does not continue to update. What is the problem?

This is how I call the Datepicker and control the date being inputted into my textfield:

 @IBAction func dp(sender: UITextField) {
    var DatePickerView  : UIDatePicker = UIDatePicker()
    DatePickerView.datePickerMode = UIDatePickerMode.Date
    textfieldjobdate.inputView = DatePickerView
    DatePickerView.addTarget(self, action: Selector("handleDatePicker"), forControlEvents: UIControlEvents.ValueChanged)    
}

func handleDatePicker() {
    var DatePickerView  : UIDatePicker = UIDatePicker()
    var dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "dd MMM yyyy"
    textfieldjobdate.text = dateFormatter.stringFromDate(DatePickerView.date)
}

回答1:

Your handleDatePicker method is instantiating a new DatePicker each time it's called. You need to add a parameter to the function to pass in the sender (the DatePicker created in func dp)

@IBAction func dp(_ sender: UITextField) {
    let datePickerView = UIDatePicker()
    datePickerView.datePickerMode = .date
    sender.inputView = datePickerView
    datePickerView.addTarget(self, action: #selector(handleDatePicker(sender:)), for: .valueChanged)
}

@objc func handleDatePicker(sender: UIDatePicker) {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "dd MMM yyyy"
    textfieldjobdate.text = dateFormatter.string(from: sender.date)
}

回答2:

    let selectedDate = datePicker.date
    print(selectedDate)
    let formatter = DateFormatter()
    formatter.dateFormat = "dd/MM/yyyy"
    let strDate = formatter.string(from: selectedDate)
    self.labelDate.text = strDate

回答3:

datePicker = UIDatePicker(frame:CGRect(x: 0, y: self.view.frame.size.height-180 , width: self.view.frame.size.width, height: 200))
    self.view.addSubview(datePicker)
    datePicker.datePickerMode = UIDatePickerMode.dateAndTime
    datePicker.isHidden = true
    button.isSelected = false
    datePicker.addTarget(self, action: #selector(self.dateSelected), for: UIControlEvents.valueChanged)

 @objc func dateSelected()
{
    let dateformatter1 = DateFormatter()
    dateformatter1.dateFormat = "ccc, d MMM yyy"

    let dateString1 = dateformatter1.string(from: datePicker.date)
    print("Date Selected \(dateString1)")
    labelDate.text = dateString1

    let dateformatter2 = DateFormatter()
    dateformatter2.dateFormat = "dd-MM-yyyy"
    let dateString2 = dateformatter2.string(from: datePicker.date)
    print("Date Selected \(dateString2)")


    let dateformatter3 = DateFormatter()
    dateformatter3.dateFormat = "dd/MM/yyyy"
    let dateString3 = dateformatter3.string(from: datePicker.date)
    print("Date Selected \(dateString3)")

    let dateformatter4 = DateFormatter()
    dateformatter4.dateFormat = "dd MMMM yyyy hh:mm a"
    let dateString4 = dateformatter4.string(from: datePicker.date)
    print("Date Selected \(dateString4)")

}

This article on DatePicker and NSDateFormat helped me a lot.

来源：https://stackoverflow.com/questions/24552117/swift-using-uidatepicker-as-uitextfield-inputview-not-updating

标签

datepicker

nsdate

swift