正确通过选择器 Swift 5 iOS

Question

I am trying to pass a method to a view, getting an unrecognized selector exception.

The first snippet is from my view controller and I'm passing the editSelector to a view that has a property Selector.I am getting this error when I tap the edit button:

-[CalorieTracker.TitleStackView editSelector:]: unrecognized selector sent to instance 0x7fe65e612800'

I'm not sure why as it looks like I've defined it properly?

@objc private func editSelector(_ sender:UIButton!){
        print("Yeet")
    }

    lazy var titleStackView: TitleStackView = {
        let titleStackView = TitleStackView(frame: CGRect(origin: .zero, size: CGSize(width: view.bounds.width, height: 44.0)), editSelector: #selector(self.editSelector(_:)))
        titleStackView.translatesAutoresizingMaskIntoConstraints = false
        return titleStackView
    }()



class TitleStackView: UIStackView {

    init(frame: CGRect, editSelector: Selector) {
        super.init(frame:frame)
        self.editSelector = editSelector
        commonInit()
    }

    var editSelector:Selector?


    required init(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }

    private func commonInit() {
        axis = .horizontal
        alignment = .center
        addArrangedSubview(titleLabel)
        addArrangedSubview(button)
    }

    lazy var titleLabel: UILabel = {
        let label = UILabel()
        label.font = UIFont.systemFont(ofSize: UIFont.preferredFont(forTextStyle: .largeTitle).pointSize, weight: .heavy)
        label.text = "My Foods"
        label.setContentHuggingPriority(.defaultLow, for: .horizontal)
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()

    lazy var button: UIButton = {
        let buttonWidth: CGFloat = 35.0
        let button = UIButton(frame: CGRect(origin: .zero, size: CGSize(width: buttonWidth, height: buttonWidth)))
        button.setTitleColor(.systemBlue, for: .normal)
        button.setTitle("Edit", for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.widthAnchor.constraint(equalToConstant: buttonWidth).isActive = true
        button.heightAnchor.constraint(equalToConstant: buttonWidth).isActive = true
        button.layer.masksToBounds = true
        button.isUserInteractionEnabled = true
        button.addTarget(self, action: self.editSelector!, for: .touchUpInside)
        return button
    }()
}

Answer 1

As you set the target as the class

button.addTarget(self, action: self.editSelector!, for: .touchUpInside)

which doesn't contain the selector, btw you should only pass a delegate and call a method inside the target class

weak var delegate:VCName?

init(frame: CGRect, delegate: Any) {
   super.init(frame:frame)
   self.delegate = delegate

then

button.addTarget(delegate!, action: self.editSelector!, for: .touchUpInside)

and add the selector impkenetation inside the calling class

Answer 2

Seems you are only passing the selector. You would also need to pass the target which is the view controller and not the view.

init(frame: CGRect, target: Any, editSelector: Selector) {
    super.init(frame:frame)
    self.target = target
    self.editSelector = editSelector
    commonInit()
}

var target:Any?
var editSelector:Selector?

And modify initialization as follows:

lazy var titleStackView: TitleStackView = {
    let titleStackView = TitleStackView(frame: CGRect(origin: .zero, size: CGSize(width: view.bounds.width, height: 44.0)), target: self, editSelector: #selector(self.editSelector(_:)))
    titleStackView.translatesAutoresizingMaskIntoConstraints = false
    return titleStackView
}()

I have got a better approach than the above, remove the custom init method and use below code:

lazy var titleStackView: TitleStackView = {
    let titleStackView = TitleStackView(frame: CGRect(origin: .zero, size: CGSize(width: view.bounds.width, height: 44.0)))
    titleStackView.button.addTarget(self, action: #selector(self.editSelector(_:)), for: .touchUpInside)
    titleStackView.translatesAutoresizingMaskIntoConstraints = false
    return titleStackView
}()