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

If you need to set rootViewController with some animations, here is the code:

guard let window = UIApplication.shared.keyWindow else {
    return
}

guard let rootViewController = window.rootViewController else {
    return
}

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "MainTabbar")
vc.view.frame = rootViewController.view.frame
vc.view.layoutIfNeeded()

UIView.transition(with: window, duration: 0.3, options: .transitionCrossDissolve, animations: {
    window.rootViewController = vc
}, completion: { completed in
    // maybe do something here
})

Answer 2

Swift 3 AppDelegate file:::

@IBAction func btnGoBack(_ sender: UIButton){

   self.goToHomeVC()
}

func goToHomeVC(){

    let storyboard = UIStoryboard(name: "Main", bundle: nil)

    let viewController = storyboard.instantiateViewController(withIdentifier :"HomeVC") as! HomeVC

    let navController = UINavigationController.init(rootViewController: viewController)

    if let window = self.appDelegate.window, let rootViewController = window.rootViewController {

        var currentController = rootViewController

        while let presentedController = currentController.presentedViewController {

            currentController = presentedController
        }

        currentController.present(navController, animated: true, completion: nil)
    }
}

Answer 3

You can try out this code

func switchRootViewController(rootViewController: UIViewController, animated: Bool, completion: (() -> Void)?) {
    guard let window = UIApplication.shared.keyWindow else { return }
    if animated {
        UIView.transition(with: window, duration: 0.5, options: .transitionCrossDissolve, animations: {
            let oldState: Bool = UIView.areAnimationsEnabled
            UIView.setAnimationsEnabled(false)
            window.rootViewController = rootViewController
            UIView.setAnimationsEnabled(oldState)
        }, completion: { (finished: Bool) -> () in
            if (completion != nil) {
                completion!()
            }
        })
    } else {
        window.rootViewController = rootViewController
    }
}

Answer 4

Swift 4.2

May be you should try this

let mainStoryBoard = UIStoryboard(name: "Main", bundle: nil)
let redViewController = mainStoryBoard.instantiateViewController(withIdentifier: "respectiveIdentifier") as! ViewController
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.window?.rootViewController = redViewController

Answer 5

For swift 4.0.

In your AppDelegate.swift file in didfinishedlaunchingWithOptions method, put the following code.

var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    window = UIWindow(frame: UIScreen.main.bounds)
    window?.makeKeyAndVisible()

    let rootVC = MainViewController() // your custom viewController. You can instantiate using nib too. UIViewController(nib name, bundle)

    let navController = UINavigationController(rootViewController: rootVC) // Integrate navigation controller programmatically if you want
    window?.rootViewController = navController

    return true
}

Hope it will work just fine.

Answer 6

Any view controller you want to set root just call the below function like

  UIApplication.shared.setRootVC(vc)

  extension UIApplication {

    func setRootVC(_ vc : UIViewController){

        self.windows.first?.rootViewController = vc
        self.windows.first?.makeKeyAndVisible()

      }
  }