ios - 如何使用 UITableViewCell 的委托(delegate)方法设置 UISlider

Question

我正在设置一个 MainViewController 和一个 PopUpViewController。

在 MainVC 中，我有一个 slider ，代表从 0 到 800 厘米的高度。在这里我还有 2 个标签，分别代表该厘米在 Feets+Inches 和 Meters+Cenmeters 中的转换。

在 HeightTableViewCell 中，我拥有所有 socket 和 slider ，并且我有一个委托(delegate)与 MainVC 通信。

在 PopUpViewController 中，我有一个保存按钮和 3 个 UITextFields(厘米、英尺和英寸)。当我按下保存按钮时，我想在 MainVC 中设置具有正确值的 slider ，并在标签中显示转换。

因为我无法访问 TableViewCell 中的 UISlider，所以我需要如何使用该委托(delegate)方法设置 UISlider？

我已经尝试与代表传递数据。还有其他更好的方法吗？

这是我的 MainVC:

class MainViewController: UIViewController {

    var sliderValue: Float = 0.0    

    override func viewDidLoad() {
        super.viewDidLoad()
    }
}

extension MainViewController: UITableViewDelegate, UITableViewDataSource {

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "heightCell", for: indexPath) as! HeightTableViewCell
        cell.configVehicleHeightCell(sliderValue)
        cell.delegate = self

        return cell
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        switch indexPath.row {
        case 0: return 150
        default:
            return 150
        }
    }
}

// Receive data from the Cell to MainVC
extension MainViewController: HeightCellDelegate {

    func heightSliderValueChanged(_ slider: UISlider, _ feetsLabel: UILabel, _ metersLabel: UILabel) {

        let currentValue = Int(slider.value)
        let meters = currentValue / 100
        let centimeters = currentValue % 100
        let inches = currentValue < 3 ? 0 : round(Double(currentValue) / 2.54)
        let feet = round(inches / 12)
        let inch = round(inches.truncatingRemainder(dividingBy: 12))

        feetsLabel.text = "\(feet) ft" + " \(inch)\""
        metersLabel.text = "\(meters) m" + " \(centimeters) cm"
    }
}

// Receive data (centimeters) from the PopUp to MainVC
extension MainViewController: HeightPopUpDelegate {

    func receiveHeightMetric(centimeters: Float?) {
        print("\n\nMetric Data received")
        print("Centimeters: \(centimeters ?? 0)")

        sliderValue = Float(centimeters ?? 0)
        tableView.reloadData()
    }

    func receiveHeightImperial(feet: Int?, inches: Int?) {

        print("\n\nImperial Data received")
        print("Feet: \(feet ?? 0)")
        print("Inches: \(inches ?? 0)")
    }

    // Receive the data from PopUpViewController
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        if segue.identifier == "goToHeight" {
            let vc: PopUpViewController = segue.destination as! PopUpViewController
            vc.delegate = self
        }
    }
}

这是我的 MainVC 单元格:

protocol HeightCellDelegate {
    func heightSliderValueChanged(_ slider: UISlider, _ feetsLabel: UILabel, _ metersLabel: UILabel)
}

class HeightTableViewCell: UITableViewCell {

    // Interface Links
    @IBOutlet weak var heightLabelTitle: UILabel!
    @IBOutlet weak var heightSlider: UISlider!
    @IBOutlet weak var heightFeetsLabel: UILabel!
    @IBOutlet weak var heightMetersLabel: UILabel!

    // Properties
    var delegate: HeightCellDelegate?

    override func awakeFromNib() {
        super.awakeFromNib()
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
    }

   func configVehicleHeightCell(_ value : Float){

    heightSlider.value = value
    heightLabelTitle.text = "Height"


    let meters  = Int((value) / 100)
    let centimeters  = Int(value.truncatingRemainder(dividingBy: 100))
    let inches = Int(value) < 3 ? 0 : round((value) / 2.54)
    let feet = Int(round(inches / 12))
    let inch = Int(round(inches.truncatingRemainder(dividingBy: 12)))

    heightFeetsLabel.text = "\(feet) ft" + " \(inch)\""
    heightMetersLabel.text = "\((meters)) m" + " \((centimeters)) cm"
}

    @IBAction func heightValueChanged(_ sender: UISlider) {

        configVehicleHeightCell(sender.value)
    }
}

这是我的 PopUpVC 代码:

protocol HeightPopUpDelegate {
    func receiveHeightMetric(centimeters: Int?)
    func receiveHeightImperial(feet: Int?, inches: Int?)
}

class PopUpViewController: UIViewController {

    // Interface Links
    @IBOutlet weak var centimetersTextField: UITextField!
    @IBOutlet weak var feetTextField: UITextField!
    @IBOutlet weak var inchesTextField: UITextField!
    @IBOutlet weak var labelForOr: UILabel!
    @IBOutlet weak var popUpView: UIView!
    @IBOutlet weak var cancelBtnOutlet: UIButton!
    @IBOutlet weak var saveBtnOutlet: UIButton!

    // Properties
    var delegate: HeightPopUpDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
        setupViews()
    }

    // Dismiss the popup when user press the Cancel btn
    @IBAction func cancelBtnTapped(_ sender: UIButton) {

        dismiss(animated: true, completion: nil)
    }

    // Save the data and send it back when user press the Save btn
    @IBAction func saveBtnTapped(_ sender: UIButton) {

        checkImperialOrMetricTextfields()
        dismiss(animated: true, completion: nil)
    }

    // Check if the textfields contains Metric or Imperial height. If everything is OK then send the data back.
    func checkImperialOrMetricTextfields(){

        if ((!(centimetersTextField.text?.isEmpty)!) && (!(feetTextField.text?.isEmpty)! || !(inchesTextField.text?.isEmpty)!)) {

            showAlertWithTitle(title: "Error", message: "Enter either metric OR imperial height.")
            clearTextFields()
        }
        if ((centimetersTextField.text?.isEmpty)! && (feetTextField.text?.isEmpty)! && (inchesTextField.text?.isEmpty)!) {

            showAlertWithTitle(title: "Error", message: "Enter either metric OR imperial height.")
            clearTextFields()
        }
        else{
            sendDataBack()
        }
    }

    // Clear textfields
    func clearTextFields(){

        centimetersTextField.text = ""
        feetTextField.text = ""
        inchesTextField.text = ""
    }

    // Function used to send data back from the PopUp to MainVC
    func sendDataBack(){

        if delegate != nil{
            delegate?.receiveHeightMetric(centimeters: Int(centimetersTextField?.text ?? "0"))
            delegate?.receiveHeightImperial(feet: Int(feetTextField?.text ?? "0"), inches: Int(inchesTextField?.text ?? "0"))
        }
    }

    // Setup the design for outlets
    func setupViews(){

        popUpView.layer.cornerRadius = 20
        popUpView.layer.masksToBounds = true

        cancelBtnOutlet.layer.cornerRadius = 5
        cancelBtnOutlet.layer.borderWidth = 0.5
        cancelBtnOutlet.layer.borderColor = UIColor.black.cgColor

        saveBtnOutlet.layer.cornerRadius = 5
        saveBtnOutlet.layer.borderWidth = 0.5
        saveBtnOutlet.layer.borderColor = UIColor.black.cgColor
    }

    // Function to hide the Popup when the user click anywhere on the screen
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        let touch = touches.first
        if touch?.view == self.view {
            dismiss(animated: true, completion: nil)
        }
    }

    // Show an alert view with Title
    func showAlertWithTitle(title: String = "", message: String) {
        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
        let OKAction = UIAlertAction(title: "OK", style: .default, handler: nil)
        alertController.addAction(OKAction)
        self.present(alertController, animated: true, completion: nil)
    }
}

目前，当我在 PopUp 中设置一些内容并单击“保存”时，我会在控制台中获取该文本字段的值:

Metric Data received
Centimeters: 0

Imperial Data received
Feet: 23
Inches: 45

如果对任何人有帮助，这里是这个小例子的链接: https://github.com/tygruletz/ImperialAndMetricMeasurement

非常感谢您阅读本文，希望我能提供正确的详细信息。

Answer 1

我做了一些更改，下面是 cm/m 的工作示例，

1. 在 HeightTableViewCell 中，在此处设置标签和 slider 。我将 Int 设置为 Float 的几个地方。

   func configVehicleHeightCell(_ value : Float){
       heightSlider.value = value
       heightLabelTitle.text = "Height"
   
   
       let meters  = Int((value) / 100)
       let centimeters  = Int(value.truncatingRemainder(dividingBy: 100))
       let inches = Int(value) < 3 ? 0 : round((value) / 2.54)
       let feet = Int(round(inches / 12))
       let inch = Int(round(inches.truncatingRemainder(dividingBy: 12)))
   
       heightFeetsLabel.text = "\(feet) ft" + " \(inch)\""
       heightMetersLabel.text = "\((meters)) m" + " \((centimeters)) cm"
   }
   

2. 在 heightValueChanged

   上，您不再需要委托(delegate)

   @IBAction func heightValueChanged(_ sender: UISlider) {
   
       configVehicleHeightCell((sender.value))
   }
   

3. 在 MainVC 中，创建 var sliderValue : Float = 0.0

4. 在 cellForRow 中，cell.configVehicleHeightCell(sliderValue)

5. 现在终于，当用户在警报中输入数据时(以 cm 文本字段工作)

   func receiveHeightMetric(centimeters: Float?) {
       print("\n\nMetric Data received")
       print("Centimeters: \(centimeters ?? 0)")
   
       sliderValue = centimeters ?? 0
       mtTableView.reloadData()
   }
   

输出:

Edit

对于feet/inch，只做下面的事情

func receiveHeightImperial(feet: Int?, inches: Int?){
   // 1. convert feet, inch into centimeter.    
   // 2. If either of feet/inch is nil then consider it as zero, for safety
   // 3. Now, sliderValue = new_cm_value (value that you calculated from feet/inch)
   // 4. Now reloadData().
}