Swift ios set a new root view controller

Question

I wonder if its possible to set a new root VC?

My app gets init with a uinavigation controller that has a table view to be the root VC.

Then from the table v

Answer 1

How and from where are you presenting redVC?

You could make it root view controller of your UINavigationController, so you would still have ability to push and pop view controllers.

self.navigationController?.viewControllers = [self];

Answer 2

This is how you can set the nib as root view controller.

 let vc = HomeViewController(nibName: "HomeViewController", bundle: nil)
 window = UIWindow(frame: UIScreen.main.bounds)
 window?.rootViewController = vc
 window?.makeKeyAndVisible()

Answer 3

Swift 4 Answer

let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewController(withIdentifier: "YourViewController") as! YourViewController
let navigationController = UINavigationController(rootViewController: nextViewController)            
let appdelegate = UIApplication.shared.delegate as! AppDelegate
appdelegate.window!.rootViewController = navigationController

Answer 4

In order to get the code snippet from the original question to work, I had to make a change to the third line

let navigationController = self.navigationController!

I am using this code in an @IBAction in the view controller that precedes the new root view controller.

Using the original code, I was receiving an error saying that my view controller had no member called window. After looking at the documentation, I could find no property named window. I'm wondering if the original block of code above was intended to be used inside a UINavigationController file.

Here is the block in its entirety.

let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let todayViewController: TodaysFrequencyViewController = storyboard.instantiateViewControllerWithIdentifier("todaysFrequency") as! TodaysFrequencyViewController    
let navigationController = self.navigationController!
navigationController.setViewControllers([todayViewControl ler], animated: true)

Answer 5

once you are in the vc that you want to set as root, just add in your viewDidLoad:

let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.window?.rootViewController = self

*As per best practice you should check if it is already the root, if not execute the code above.

Answer 6

Link to a related question

This answer applies to usage of an existing ViewController from somewhere in the current stack without instantiating and reconfiguring a new controller.

The documentation says: The root view controller provides the content view of the window. Assigning a view controller to this property (either programmatically or using Interface Builder) installs the view controller’s view as the content view of the window. The new content view is configured to track the window size, changing as the window size changes. If the window has an existing view hierarchy, the old views are removed before the new ones are installed.

Just as the documentation says: It removes all views in the stack if the rootViewController is exchanged. No matter what's with the controller. So remove the ViewController from the stack to assure its view won't be removed.

This resulted in my case in the following solution:

    if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
        guard let pageVC = self.onboardingDelegate as? OnboardingPageViewController else { return } // my current stack is in a pageViewController, it also is my delegate
        let vc = self // holding myself
        pageVC.subViewControllers.removeLast() // removing myself from the list
        pageVC.setViewControllers([pageVC.subViewControllers[0]], direction: .forward, animated: false, completion: nil) // remove the current presented VC
        appDelegate.window?.rootViewController = vc
        vc.onboardingDelegate = nil
        appDelegate.window?.makeKeyAndVisible()
    }