我如何添加由另一个用户建议的这部分代码？

Question

这是我的原始代码：

        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]
    }
}
}

然后我被告知这样做：

” 看起来您从未将正确的文本字段设置为第一响应者。

顺便说一下，所有你的if / else if / else if ...构造都会更干净，因为你可以设置字典，按钮作为键，然后是包含数据源和选择器的结构查看该按钮：“

     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)
]

和他说：“然后像你的按钮动作一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() 
}

所以我的问题是如何将这两组新代码添加到我的原始代码并更新它？我尝试了很多方法和地点，但我在代码方面没有足够的经验，不能在我的项目中弄乱一些东西

Answer 1

此图片会有所帮助。此Red mark适用于UIPickerViewDelegate。

创建名为Swift的空ButtonData文件并复制此代码。

在ViewController中，您可以尝试这样做。

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


var buttonsDict = [UIButton : ButtonData]()
var lastPressedButton: UIButton?
@IBOutlet weak var pickerView: UIPickerView!


override func viewDidLoad() {
    super.viewDidLoad()

    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)
    ]

    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;

    // Do any additional setup after loading the view.
}

@objc func buttonClicked(sender:UIButton!) {

    lastPressedButton = sender

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

    let textField = buttonStruct.buttonTextField

    textField.inputView = pickerView

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


// STRUCT
import Foundation
import UIKit

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