Question

这是我之前在这里获得帮助的代码，我只是不能完全告诉我的代码缺少什么工作。我进行了设置，按下按钮以显示选择器视图，然后选项出现在标签中。但是，当我点击按钮时，它不会显示选择器视图。我想从我所知道的，问题是我错过了一个连接会触发一个让另一个出现，我的pickerview被设置为隐藏，并且当它应该弹出时它也会出现在堆栈视图的顶部。

    import UIKit

class CalculatorViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {

@IBOutlet weak var firstButton: UIButton!
@IBOutlet weak var secondButton: UIButton!
@IBOutlet weak var thirdButton: UIButton!
@IBOutlet weak var fourthButton: UIButton!
@IBOutlet weak var fifthButton: UIButton!
@IBOutlet weak var nextPageButton: UIButton!

@IBOutlet weak var firstTextField: UITextField!
@IBOutlet weak var secondTextField: UITextField!
@IBOutlet weak var thirdTextField: UITextField!
@IBOutlet weak var fourthTextField: UITextField!
@IBOutlet weak var fifthTextField: UITextField!

@IBOutlet weak var pickerView: UIPickerView!

var firstButtonDataSource = ["1", "2", "3", "4"];
var secondButtonDataSource = ["White", "Red", "Green", "Blue"];
var thirdButtonDataSource = ["Mike", "Steve", "Ben", "Peter"];
var fourthButtonDataSource = ["Large", "Medium", "Small", "Extra-small"];
var fithButtonDataSource = ["USA", "UK", "France", "Germany"];

var lastPressedButton: UIButton?

override func viewDidLoad() {
    super.viewDidLoad()

    firstButton.addTarget(self, action:#selector(buttonClicked(sender:)), for: .touchUpInside)
    secondButton.addTarget(self, action:#selector(buttonClicked(sender:)), for: .touchUpInside)
    thirdButton.addTarget(self, action:#selector(buttonClicked(sender:)), for: .touchUpInside)
    fourthButton.addTarget(self, action:#selector(buttonClicked(sender:)), for: .touchUpInside)
    fifthButton.addTarget(self, action:#selector(buttonClicked(sender:)), for: .touchUpInside)

    self.pickerView.dataSource = self;
    self.pickerView.delegate = self;
}

@objc func buttonClicked(sender:UIButton!) {

    lastPressedButton = sender

    if lastPressedButton == firstButton {
        firstTextField.inputView = pickerView
    } else if lastPressedButton == secondButton {
        secondTextField.inputView = pickerView
    } else if lastPressedButton == thirdButton {
        thirdTextField.inputView = pickerView
    } else if lastPressedButton == fourthButton {
        fourthTextField.inputView = pickerView
    } else if lastPressedButton == fifthButton {
        fifthTextField.inputView = pickerView
    }
}

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 1
}

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

    if lastPressedButton == firstButton {
        return firstButtonDataSource.count;
    } else if lastPressedButton == secondButton {
        return secondButtonDataSource.count;
    } else if lastPressedButton == thirdButton {
        return thirdButtonDataSource.count;
    } else if lastPressedButton == fourthButton {
        return fourthButtonDataSource.count;
    } else if lastPressedButton == fifthButton {
        return fithButtonDataSource.count;
    }

    return 0
}

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {

    if lastPressedButton == firstButton {
        return firstButtonDataSource[row];
    } else if lastPressedButton == secondButton {
        return secondButtonDataSource[row];
    } else if lastPressedButton == thirdButton {
        return thirdButtonDataSource[row];
    } else if lastPressedButton == fourthButton {
        return fourthButtonDataSource[row];
    } else if lastPressedButton == fifthButton {
        return fithButtonDataSource[row];
    }

    return ""
}

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

    if lastPressedButton == firstButton {
        self.firstTextField.text = firstButtonDataSource[row]
    } else if lastPressedButton == secondButton {
        self.secondTextField.text = secondButtonDataSource[row]
    } else if lastPressedButton == thirdButton {
        self.thirdTextField.text = thirdButtonDataSource[row]
    } else if lastPressedButton == fourthButton {
        self.fourthTextField.text = fourthButtonDataSource[row]
    } else if lastPressedButton == fifthButton {
        self.fifthTextField.text = fithButtonDataSource[row]
    }
}
}

Answer 1

看起来您从未将正确的文本字段设置为第一响应者。

顺便说一句，所有长if / else if / else if ...结构都会更干净，因为您可以设置字典，并将按钮作为键和然后是一个包含该按钮的数据源和选择器视图的结构：

struct ButtonData {
  let buttonDataSource: [String]
  let buttonTextField: UITextField
}

let buttonsDict = [
  firstButton: ButtonData(buttonDataSource: ["1", "2", "3", "4"],
    buttonTextField: firstTextField),
  secondButton: ButtonData(buttonDataSource: ["White", "Red", "Green", "Blue"],
    buttonTextField: secondTextField),
  thirdButton: ButtonData(buttonDataSource: ["Mike", "Steve", "Ben", "Peter"],
    buttonTextField: thirdTextField),
  fourthButton: ButtonData(buttonDataSource: ["Large", "Medium", "Small", "Extra-small"],
    buttonTextField: fourthTextField),
  fifthButton: ButtonData(buttonDataSource: ["USA", "UK", "France", "Germany"],
    buttonTextField: fifthTextField)
]

然后像你的按钮动作这样的代码可以使用字典：

@objc func buttonClicked(sender:UIButton!) {

    lastPressedButton = sender

    guard let buttonStruct = buttonsDict[lastPressedButton] else { return }

    let textField = buttonsStruct.buttonTextField

    textField.inputView = pickerView

    //I think this the code you need to show the picker
    textField.becomeFirstResponder() 
}

为什么我的按钮不能让我的挑选视图出现？

1 个答案: