是否有可能从Swift中的UITextField中获得UIPickerView和UIDatePicker？

Question

我是新来的Swift，请耐心等待。

首先，让我解释一下我的应用程序布局：

我有一个文本字段在屏幕上，有一个标签和一个按钮。我询问用户3个问题 - 使用“标签”显示这些问题，并且每当用户按下下一个“按钮”时（问题从数组中填充），就会出现下一个问题。

其中一个问题需要填充Picker View（因此用户可以选择一个选项）。 其中一个问题使用普通键盘。 而我需要使用日期选取器的最后一个问题。

这可能吗？如果是这样，你能告诉我如何将它添加到我的代码下面吗？

let questions = ["What is your title?", "What is your full name?", "When were you born?"] 

var currentQuestionIndex = 0 

let placeholder = ["Title", "Full name", "Date of birth"] 

var currentPlaceholderIndex = 0 

@IBAction func nextButton(sender: AnyObject) { 

    textField.hidden = false 
    textField.placeholder = placeholder[currentPlaceholderIndex] 
    barImage.hidden = false 

    // Reset text field to have no text 
    textField.text = "" 


    questionLabel.text = questions[currentQuestionIndex] 

    // Displays the questions in array 
    if currentQuestionIndex < questions.count { 
     ++currentQuestionIndex 

     // Displays the placeholder text in the textfield 
     if currentPlaceholderIndex < placeholder.count { 
      ++currentPlaceholderIndex 

     } 

     buttonLabel.setTitle("Next", forState: UIControlState.Normal) 


    } 

    else { 

     //Add some logic here to run whenever the user has answered all the questions. 

    } 

    } 

感谢您的帮助！

尼克

NEW下面的代码（从2015年4月6日）：

类的ViewController：UIViewController中，UITextFieldDelegate，UIPickerViewDataSource，UIPickerViewDelegate基于currentQuestionIndex {

var pickerData = ["Mr", "Mrs", "Miss", "Ms", "Doctor"] 

var questions = ["What is your title?", "What is your name?", "What is your DOB?"] 

var currentQuestionIndex = 0 

var datePickerView:UIDatePicker = UIDatePicker() 
var pickerView:UIPickerView = UIPickerView() 

@IBOutlet var buttonLabel: UIButton! 

@IBOutlet var questionsLabel: UILabel! 

@IBOutlet var textField: UITextField! 

@IBAction func textFieldEditing(sender: UITextField) { 

    datePickerView.datePickerMode = UIDatePickerMode.Date 
    sender.inputView = datePickerView 
    datePickerView.addTarget(self, action: Selector("datePickerValueChanged:"), forControlEvents: UIControlEvents.ValueChanged) 
} 

func datePickerValueChanged(sender: UIDatePicker) { 
    var dateformatter = NSDateFormatter() 
    dateformatter.dateStyle = NSDateFormatterStyle.LongStyle 
    textField.text = dateformatter.stringFromDate(sender.date) 
} 

@IBAction func nextButton(sender: UIButton) { 

    textField.text = "" 
    textField.hidden = false 
    buttonLabel.setTitle("Next", forState: UIControlState.Normal) 
    questionsLabel.text = questions[currentQuestionIndex] 

    if currentQuestionIndex < questions.count { 

     currentQuestionIndex++ 
    } 

    else { 
     //println("questions are complete") 
    } 
} 

func textFieldDidBeginEditing(textField: UITextField) { 

    switch currentQuestionIndex { 

    case 0: 
     self.view.addSubview(datePickerView) 

    case 2: 
     self.view.addSubview(pickerView) 
    default: 
     println("Test") 
    } 
} 


override func viewDidLoad() { 
    super.viewDidLoad() 
    buttonLabel.setTitle("Start", forState: UIControlState.Normal) 
    textField.hidden = true 
    questionsLabel.text = "" 
    textField.delegate = self 
    pickerView.delegate = self 
    pickerView.dataSource = self 


    // Do any additional setup after loading the view, typically from a nib. 
} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 

func textFieldShouldReturn(textField: UITextField) -> Bool { 
    textField.resignFirstResponder() 
    return true 
} 

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) { 
    self.view.endEditing(true) 

} 


func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int { 

return 1 
} 

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int { 

return pickerData.count 

} 

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! { 
return pickerData[row] 

} 

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) { 

textField.text = pickerData[row] 
pickerView.hidden = true 

} 

}

Answer 1

你可以将UIPickerView或UIDatePicker添加到您的UITextField例如

switch currentQuestionIndex { 
case 0: 
    // TODO: Add UIPickerView 
case 2: 
    // TODO: Add UIDatePicker 
} 

编辑：更多的解释

起初，符合UITextFieldDelegate和实施textFieldDidBeginEditing(:) 因为你想获得通知您必须实现该方法时的UITextField实例获得第一个响应状态

而且，将UITextField实例的delegate属性设置为self或者您想要放置并实施的任何实例/对象textFieldDidBeginEditing(:)

然后编写代码

func textFieldDidBeginEditing(_ textField: UITextField) { 
    switch currentQuestionIndex { 
    case 0: 
     // TODO: Add UIPickerView 
     // Add it for example at the bottom your view self.view.addSubview(pickerViewInstance) 
     // or add it as the subview of UIPopoverController instance that is added to your UITextField instance 
    case 2: 
     // TODO: Add UIDatePicker 
     // Add it for example at the bottom your view self.view.addSubview(datePickerInstance) 
     // or add it as the subview of UIPopoverController instance that is added to your UITextField instance 
    } 
} 

记住，当你想添加另一种观点认为，以你的UIPopoverViewController删除添加的视图。

编辑：添加真实世界中的实现

class NewCaseViewController : UIViewController { 
    . . . 

    @IBOutlet weak var textField: UITextField // TODO: Initialize it properly in designated initializer 
    var popoverController: UIPopoverController! // TODO: Initialize it 

    . . . 
} 


class PopoverContentManager : UIViewController { 
    . . . 

    var pickerView: UIPickerView // TODO: Initialize it properly 
    var datePicker: UIDatePicker // TODO: Initialize it properly 

    . . . 
} 

extension NewCaseViewController : UITextFieldDelegate { 
    func textFieldBeginEditing(_ textField: UITextField) { 
     println(__FUNCTION__) 

     var popover = PopoverContentManager() 

     switch self.currentQuestionIndex { 
      case 0: 
       popover.datePicker.hidden = true 

       self.popoverController = init(contentViewController: popOver) 

       self.popoverController.presentPopoverFromRect(self.textField.bounds, inView: self.textField, permittedArrowDirections: UIPopoverArrowDirectionDown, animated: true) 

       self.popoverController.popoverContentSize = CGSizeMake(120, 90) 
      case 1: 
       popover.pickerView.hidden = true 

       self.popoverController = init(contentViewController: popOver) 

       self.popoverController.presentPopoverFromRect(self.textField.bounds, inView: self.textField, permittedArrowDirections: UIPopoverArrowDirectionDown, animated: true) 

       self.popoverController.popoverContentSize = CGSizeMake(120, 90) 
      } 
     } 
}