UIButton selector function weird behaviour - ios

Question

In my application, i had a UIButton that works perfectly fine on
XCode simulator (mostly with iOS 11.4 and iOS 14.5)
physical device (iPhone 6: iOS 12.5, iPhone 7: iOS 14.5, iPhone 12: iOS 14.5)
My trouble is that some of my client's phone does not work as expected
iPhone XR: iOS 14.5
iPhone XS MAX: iOS 14.5
iPhone 8 Plus: iOS 14.4
Expected Behaviour -
User clicked the button > call selector function > trigger callback > go to another view controller
Client's Phone Behaviour -
User clicked the button, and nothing happen. I'm pretty sure the app had captured the touch, because there's some shadow on button pressed.
Below is the sample codes i use
MainViewController : The purpose of this controller is to swap between different child view controller
class MainViewController: UIViewController {
private let containerView: UIView = {
let view = UIView(frame: .zero)
return view
}()
private var currentContentVC: UIViewController
init() {
let childVC = ChildViewController()
currentContentVC = childVC
childVC.delegate = self
super.init(nibName: nil, bundle: nil)
}
override func loadView() {
super.loadView()
view.addSubview(containerView);
containerView.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0).isActive = true
containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 0).isActive = true
currentContentVC.view.frame = containerView.bounds
addChild(currentContentVC)
containerView.addSubview(currentContentVC.view)
}
}
extension MainViewController: ChildViewControllerCallBack {
func btnPressed() {
let oldVC = currentContentVC
let newVC = OtherChildViewController()
newVC.delegate = self
newVC.view.frame = containerView.bounds
currentContentVC = newVC
switchChildController(from: oldVC, to: currentContentVC, options: options)
}
}
ChildViewController : Controller that consist of the troubled button
class ChildViewController: UIViewController {
weak var delegate: ChildViewControllerCallBack?
private let mainV: UIView = {
let view = UIView()
return view
}()
private let detailV: UIView = {
let view = UIView()
return view
}()
private let myBtn: UIButton = {
let button = UIButton(type: .custom)
let buttonImage = UIImage(named: "btn_gold_square")
let imageRatio = (buttonImage?.size.width)! / (buttonImage?.size.height)!
button.setBackgroundImage(buttonImage, for: .normal)
button.titleLabel?.font = Font.dynamicXSmallFont
button.titleLabel?.numberOfLines = 2
button.titleLabel?.textAlignment = .center
button.setTitle(title, for: .normal)
button.setTitleColor(Colors.black, for: .normal)
let imageWidth = (SharedData.shared().dialogWidth + (SharedData.shared().dialogWidth * 0.1)) * 0.25
let imageHeight = imageWidth / imageRatio
button.widthAnchor.constraint(equalToConstant: imageWidth).isActive = true
button.heightAnchor.constraint(equalToConstant: imageHeight).isActive = true
button.addTarget(self, action: #selector(btnPressed), for: .touchUpInside)
return button
}()
protocol hildViewControllerCallBack: class {
func btnPressed()
}
override func loadView() {
super.loadView()
view.addSubview(mainV);
mainV.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
mainV.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0).isActive = true
mainV.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
mainV.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 0).isActive = true
[detailV, myBtn].forEach { mainV.addSubview(0) }
detailV.topAnchor.constraint(equalTo: mainV.topAnchor, constant: 0).isActive = true
detailV.leadingAnchor.constraint(equalTo: mainV.leadingAnchor, constant: 0).isActive = true
detailV.bottomAnchor.constraint(equalTo: mainV.bottomAnchor, constant: 0).isActive = true
detailV.widthAnchor.constraint(equalTo: mainV.widthAnchor, multiplier: 0.7).isActive = true
detailV.centerYAnchor.constraint(equalTo: mainV.centerYAnchor).isActive = true
myBtn.leadingAnchor.constraint(equalTo: detailV.trailingAnchor, constant: 0).isActive = true
myBtn.trailingAnchor.constraint(equalTo: mainV.trailingAnchor, constant: 0).isActive = true
}
#objc private func btnPressed(){
delegate?.btnPressed()
}
}

Answer 1

Finally solved it, the problematic line is this
private let myBtn: UIButton = {
All I have to do is change it to
lazy var myBtn: UIButton = {
If you wondering what and how does it work, for the long version, please refer to this article.
The short version:
A lazy stored property is a property whose initial value is not calculated until the first time it is used. You indicate a lazy stored property by writing the lazy modifier before its declaration.