Updating navigation bar button item title outside of viewdidload - ios

Question

I am creating a navigation bar in viewDidLoad method with following code:
let backButtonImage = UIImage(named: "backButton")
normalButton = UIButton(frame: CGRect(x: 0, y: 0, width: backButtonImage!.size.width, height: backButtonImage!.size.height))
normalButton.setImage(backButtonImage, for: .normal)
normalButton.setTitleColor(.systemBlue, for: .normal)
normalButton.contentHorizontalAlignment = .leading
normalButton.contentVerticalAlignment = .center
normalButton.titleEdgeInsets = UIEdgeInsets(top: 0, left: 0.0, bottom: 0.0, right: 0.0)
let backBarButton = UIBarButtonItem(customView: normalButton)
backBarButton.tintColor = .systemBlue
item.leftBarButtonItems = [backBarButton]
navigationBar.isTranslucent = false
navigationBar.barTintColor = .white
self.view.addSubview(navigationBar)
navigationBar.translatesAutoresizingMaskIntoConstraints = false
navigationBar.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
navigationBar.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
navigationBar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
navigationBar.items = [item]
navigationBar.delegate = self
But i want to update normalButton title when user touches an another button inside the view. I tried following code:
if let letnavItem = navigationBar.items?[0],let bb = letnavItem.leftBarButtonItems?[0] {
if let but = bb.customView, let but2 = but as? UIButton {
print("counter: \(counter)")
but2.setTitle("asd", for: .normal)
}
}
But it is not working. But if i run the second code in viewDidLoad method right after the navigationBar.delegate line, it is working well.
Why is it not working outside of the viewDidLoad?

Answer 1

All above code is correct just you need to remove image from the button before setting off the button text like this:
but2.setImage(nil, for: .normal)
but2.setTitle("asd", for: .normal)