iOS: Hide the navigation bar for only one viewcontroller which is root of the UINavigationController?

Question

I want to hide the navigationbar for only one viewcontroller which is the root viewcontroller of the UINavigationController.

Currently I am using below code to hide the navigation bar for a particular viewcontroller.

• To hide the navigationbar,

    override func viewWillAppear(_ animated: Bool) {
        self.navigationController?.isNavigationBarHidden = true
        super.viewWillAppear(animated)
    }

• To show the navigationbar for other viewcontrollers,

    override func viewWillDisappear(_ animated: Bool) {
        self.navigationController?.isNavigationBarHidden = false
        super.viewWillDisappear(animated)
    }

When I am trying to use this code, the app is being crashed in iOS 13 devices because of threading violation: expected the main thread.

Please checkout the issue which I am getting when I use the above code to hide the navigationbar,

iOS 13: threading violation: expected the main thread

Please let me know if there is any other way to hide the navigationbar for only one viewcontroller.

Affray

You already asked this question once here. Don't ask multiple times about the same problem. Close this question. – Belted

Answer 1

I got the another way to hide/show navigationbar from one of my friend.

• Set a delegate for the NavigationController:

navigationController.delegate = self

• Hide/Show navigationbar for each ViewController all in one place

func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
    let hide = (viewController is YourVC)
    navigationController.setNavigationBarHidden(hide, animated: animated)
}

Affray

Answer 2

import UIKit
 class ViewController: UIViewController {

 override func viewWillAppear(_ animated: Bool){
    super.viewWillAppear(animated)
    self.navigationController?.isNavigationBarHidden = true
   }
 override func viewWillDisappear(_ animated: Bool){
    super.viewWillDisappear(animated)
    self.navigationController?.isNavigationBarHidden = false
   }

}

Thromboplastin

Answer 3

You can make it transparent (Completely invisible) when viewWillApper get called and back to normal when view willDisappear get called. Here are helper functions.

func makeNaBarTransparent() {
      navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
      navigationController?.navigationBar.shadowImage = UIImage()
      navigationController?.navigationBar.isTranslucent = true
  }


 func restoreNavigationBarToDefault() {
      navigationController?.navigationBar.setBackgroundImage(nil, for: .default)
      navigationController?.navigationBar.shadowImage = nil
  }

USAGE

 import UIKit
class ViewController: UIViewController {

 override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        makeNaBarTransparent()
    }

 override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        restoreNavigationBarToDefault()
    }

}

Franny