Swift prefersLargeTitles collapsed when WKWebview loaded - ios

Question

I create a NavigationController with a large title NavigationBar with this code.
class NavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
let appearance = UIBarButtonItem.appearance()
appearance.setBackButtonTitlePositionAdjustment(UIOffset.init(horizontal: 0.0, vertical: -60), for: .default)
self.navigationBar.barTintColor = UIColor.white
self.navigationBar.prefersLargeTitles = true
self.navigationBar.isTranslucent = true
self.navigationBar.tintColor = UIColor.black
}
}
Everything works fine, but when my WKWebView is loaded, somehow the large title bar collapsed automatically without any ScrollViewDelegate code. Please take a look at my gif here to clarify
Here is my WKWebView code.
class resultViewController: UIViewController
{
private var webView: WKWebView!
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.white
webView = WKWebView(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height))
webView.navigationDelegate = self
webView.scrollView.delegate = self
self.view.addSubview(webView)
let url = URL(string: "https://google.com")
webView.load(URLRequest(url: url!))
}
}
I expect to keep the large title bar visible at first screen, and only collapse when scrolling up event triggered.
Any idea?

Answer 1

The reason of this issue is your navigationBar height is changing when you webView starts loading the page. so using viewLayoutMarginsDidChange() we can change navigationBar height.
viewLayoutMarginsDidChange() Called to notify the view controller that the layout margins of its root view changed. This method will get called every time when navigationBar height changes.
Refer This Answer https://stackoverflow.com/a/57430695/7301439