Swift 5 custom navigation bar cover title and buttons - ios

Question

After seeking a lot and trying many solutions, nope fixed my problem.
In my app I customized the UINavigationController in order to have blur effect:
import UIKit
class CustomNavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .regular))
visualEffectView.frame = (self.navigationBar.bounds.insetBy(dx: 0, dy: -40).offsetBy(dx: 0, dy: -40))
self.navigationBar.isTranslucent = true
self.navigationBar.setBackgroundImage(UIImage(), for: .default)
self.navigationBar.addSubview(visualEffectView)
self.navigationBar.sendSubviewToBack(visualEffectView)
}
}
Then in Main.storyboard I selected the customized class for the navigation controller item.
The blur effect works properly, the status icons are correctly visible, but not the standard navigation bar items: left button, title and right button.
For a moment they appears but soon after the customized navigation bar covers them.
I'm using Xcode 12.4 and I'm running the app on iPhone Xr.
How can I show the navigation bar elements again?
Thanks a lot in advance.

Answer 1

Translucent navigation bars in iOS already blur the content behind the bar, so you shouldn't need to add a UIVisualEffectView nor set a backgroundImage.
If you modify your code to just:
override func viewDidLoad()
{
super.viewDidLoad()
self.navigationBar.isTranslucent = true
}
does this not achieve the visual effect you're looking for?
If not, please try the following adjustment to your methodology:
override func viewDidLoad()
{
super.viewDidLoad()
self.navigationBar.isTranslucent = true
// create a UIImageView
let backgroundImage: UIImageView = UIImageView()
backgroundImage.autoresizingMask = [.flexibleWidth, .flexibleHeight]
backgroundImage.image = UIImage()
// add a blur effect to the ImageView
let visualEffectView: UIVisualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .regular))
visualEffectView.frame = (self.navigationBar.bounds.insetBy(dx: 0, dy: -40).offsetBy(dx: 0, dy: -40))
backgroundImage.addSubview (visualEffectView)
// and set that as your backgroundImage on the navigationBar
self.navigationBar.setBackgroundImage(backgroundImage.image, for: .default)
}
this adds the blur effect to the backgroundImage. This seems to work for me, but the visual effect is no different than just using my first suggestion, likely because backgroundImage.image == nil.
This is certainly an improved approach in that it doesn't add unexpected subviews into the UINavigationBar view hierarchy, and I observed both methods did not affect the visibility of the bar controls.