How to hide the navigation bar as scroll down, when constraints are programmatically?

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Created Jun ’20

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I'm trying to hide the navigation bar when the scroll is down, and unhide again when the scroll is up. But when I scroll up the navigation bar doesn't appear again.
How can I fix that behavior?

The first detail is that I'm not using story board.

The second one is that I'm separating all my UI elements from my ViewController, so I have a UIView class where I'm declaring all my UI elements, and in my ViewController I only call my UIView. Here is my code.

Code Block class RegisterUIView: UIView {
		lazy var scrollView: UIScrollView = {
				let scroll: UIScrollView = UIScrollView()
				scroll.contentSize = CGSize(width: self.frame.size.width, height: self.frame.size.height)
				scroll.translatesAutoresizingMaskIntoConstraints = false
				return scroll
		}()
	/*Here other UI elements*/
	override init(frame: CGRect) {
			super.init(frame: frame)
			initComponents()
	 	}
	required init?(coder: NSCoder) {
      super.init(coder: coder) 
    }
	func initComponents() {
			addComponents()
			setupLayout()
		}
	 func addComponents() {
			addSubview(scrollView)
	}
		func setupLayout() {
			NSLayoutConstraint.activate([
						scrollView.topAnchor.constraint(equalTo: self.topAnchor),
						scrollView.leadingAnchor.constraint(equalTo: self.leadingAnchor),
						scrollView.bottomAnchor.constraint(equalTo: self.bottomAnchor),
						scrollView.trailingAnchor.constraint(equalTo: self.trailingAnchor)
				])			
	}
}

My ViewController

Code Block class RegisterViewController: UIViewController {
		private let registerView: RegisterUIView = {
				let view = RegisterUIView(frame: .zero)
				view.translatesAutoresizingMaskIntoConstraints = false
				return view
		}()
		override func viewWillAppear(_ animated: Bool) {
				super.viewWillAppear(animated)
				self.navigationController?.hidesBarsOnSwipe = true
		}
		
		override func viewWillDisappear(_ animated: Bool) {
				super.viewWillDisappear(animated)
				self.navigationController?.hidesBarsOnSwipe = false
		}
		override func viewDidLoad() {
				super.viewDidLoad()
				setupLayout()	
		}
		func setupLayout() {
				view.addSubview(registerView)
				NSLayoutConstraint.activate([
						registerView.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor),
						registerView.leadingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.leadingAnchor),
						registerView.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor),
						registerView.trailingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.trailingAnchor)
				])
		}