使用未解析的标识符“ LaunchScreenViewController”

Question

I have one issues, i want to restart my app, and i have only one solution how to do it.

It's only pop to rootViewController.

My code:

   func restartApplication() {
    let viewController = LaunchScreenViewController()
    let navCtrl = UINavigationController(rootViewController: viewController)

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

    navCtrl.view.frame = rootViewController.view.frame
    navCtrl.view.layoutIfNeeded()

    UIView.transition(with: window, duration: 0.3, options: .transitionCrossDissolve, animations: {
        window.rootViewController = navCtrl
    })

}

But i get this error:

Use of unresolved identifier 'LaunchScreenViewController'

What is the problem?

Answer 1

For xif Just replace the line of code with this ..

let viewController = LaunchScreenViewController(nibName: "LaunchScreenViewController", bundle: nil)

Instead of this one ..

let viewController = LaunchScreenViewController()

For Storyboard

// global declaration 
let kApplicationDelegate = UIApplication.shared.delegate as! AppDelegate

// use this extension
extension UIViewController{
    func changeStoryboardTo(){
        let nav = UINavigationController(rootViewController: self)
        UIView.transition(with: (kApplicationDelegate.window)!,
                      duration:0.5,
                      options:UIViewAnimationOptions.transitionFlipFromLeft,
                      animations: {
                        kApplicationDelegate.window?.rootViewController = nav
                        // do something
        }, completion:{
           finished in
            // competion code
        })*/

    }
}

extension UIStoryboard{
 func getControllerInstance(storyBoardName : String, identifire : String) -> UIViewController {
        let objStoryBoard = UIStoryboard(name: storyBoardName, bundle: Bundle.main)
        let vc = objStoryBoard.instantiateViewController(withIdentifier: identifire)
    return vc
    }
}

Calling

_ = UIStoryboard().getControllerInstance(storyBoardName: "yourStoryboardName", identifire: "yourViewControllerIdentifire").changeStoryboardTo()

Answer 2

如果您正在使用情节提要，并且已经为特定的ViewController设置了ViewController标识符

let viewController = UIStoryboard(name: "LaunchScreenStoryboard", bundle: nil).instantiateViewControllerWith(identifier: "LaunchScreenViewController") as! LaunchScreenViewController