Navigation Controller not releasing memory, memory leak? - swift

Question

Ive created a navigation which pushes a view controller that contains an image view and a button which adds the same view controller each time the button is tapped. After each tap the memory grows and after each back tap the memory is not released despite deinit being called. There is nothing in the code that points to a memory leak is there something I am missing thank you?
complete project repository
class ViewController: UIViewController {
lazy var nextButton:UIButton? = {
let button = UIButton(type: .roundedRect)
button.setTitle("Next", for: .normal)
button.addTarget(self, action: #selector(nextButtonTapped), for: .touchUpInside)
button.translatesAutoresizingMaskIntoConstraints = false
button.backgroundColor = UIColor.red
return button
}()
lazy var imageView:UIImageView? = {
let image = #imageLiteral(resourceName: "DJI_0014")
let imageView = UIImageView(image: image)
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
guard let imageView = self.imageView, let nextButton = self.nextButton else{
print("imageView, nextButton are nil")
return
}
self.view.backgroundColor = UIColor.white
self.view.addSubview(imageView)
NSLayoutConstraint.activate([
imageView.topAnchor.constraint(equalTo:self.view.topAnchor),
imageView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
imageView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
imageView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor)])
view.addSubview(nextButton)
NSLayoutConstraint.activate([nextButton.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
nextButton.centerYAnchor.constraint(equalTo: self.view.centerYAnchor, constant: 0),nextButton.heightAnchor.constraint(equalToConstant: 200),nextButton.widthAnchor.constraint(equalToConstant: 200)])
}
#objc func nextButtonTapped(){
print("next button tapped")
self.navigationController?.pushViewController(ViewController(), animated: true)
}
deinit {
print("view controller is deinitialized")
}
}
Ive viewed other questions listed below and tried to adopt their suggestions but none of them seemed to help
Navigation arc memory not released
Memory leak issue in navigation controller

Answer 1

Finally, I have identified the problem, which is from the navigationBar:
navigationController?.setNavigationBarHidden(true, animated: false)
This code will remove all the issues on large memory residues. Other parts of codes are fine. and in this situation, all memory will keep around 19M all the time.
I tried to use a navigationDelegate to do the transition and found there is a crash overlooked by the system and stated that if repeating push vc will make NavigationBar not layout well. So I turn it hidden and the problem has gone. But if you do need navigationBar or its animation, there would be a lot of work to do here.
But the memory issue has been found.