Hide UINavigationController's navigationBar when the root controller is a UIHostingController - ios

Question

I am struggling to hide the navigationBar, which would properly be hidden if the root controller wasn't a SwiftUI UIHostingController.
I tried the following:
Setting navigationController.isNavigationBarHidden = true after creating it, at viewDidLoad and viewWillAppear.
Adding both .navigationBarHidden(true) and .navigationBarBackButtonHidden(true) for the UIHostingController's rootView.
Could it be an Apple bug? I am using Xcode 11.6.
All my attempts together:
class LoginController: UINavigationController, ObservableObject
{
static var newAccount: LoginController
{
let controller = LoginController()
let view = LoginViewStep1()
.navigationBarHidden(true)
.navigationBarBackButtonHidden(true)
controller.viewControllers = [UIHostingController(rootView: view)]
controller.isNavigationBarHidden = true
return controller
}
override func viewWillAppear(_ animated: Bool)
{
super.viewWillAppear(animated)
self.isNavigationBarHidden = true
}
override func viewDidLoad()
{
super.viewDidLoad()
self.isNavigationBarHidden = true
}
}
struct LoginViewStep1: View
{
// ...
var body: some View
{
VStack {
// ...
}
.navigationBarHidden(true)
.navigationBarBackButtonHidden(true)
}
}

Answer 1

Here is a solution. Tested with Xcode 11.4 / iOS 13.4
Modified your code:
class LoginController: UINavigationController, ObservableObject
{
static var newAccount: LoginController
{
let controller = LoginController()
let view = LoginViewStep1()
controller.viewControllers = [UIHostingController(rootView: view)]
// make it delayed, so view hierarchy become constructed !!!
DispatchQueue.main.async {
controller.isNavigationBarHidden = true
}
return controller
}
}
struct LoginViewStep1: View
{
var body: some View
{
VStack {
Text("Hello World!")
}
}
}
tested part in SceneDelegate
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
window.rootViewController = LoginController.newAccount
self.window = window
window.makeKeyAndVisible()
}

Answer 2

Alternate solution is to use UINavigationControllerDelegate:
func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
// Required because pushing UIHostingController makes the navigationBar appear again
navigationController.isNavigationBarHidden = true
}
Tested with iOS 14.5 - Xcode 12.5