更改 ViewController 并重新启动应用程序

Question

我制作了两个 ViewController，如何将 rootViewController 从 ViewController() 更改为 MainView()？这是我在 SceneDelegate

中的代码

guard let windowScene = (scene as? UIWindowScene) else { return }
window = UIWindow(windowScene: windowScene)
window?.makeKeyAndVisible()
window?.backgroundColor = UIColor.black
if isNewUser == true {
     window?.rootViewController = ViewController()
} else {
     window?.rootViewController = MainView()
}

当我运行应用程序测试 isNewUser = true 和 isNewUser = false 时，这工作正常。

在我的ViewController

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        //Show the welcome screen, blah.
        //Accept the location, blah.
        //After accepted everything, change isNewUser to false in UserDefault.Standard
        print("App is restart")
    }
}

class MainView: UITabBarController, UITabBarControllerDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        print("Welcome to AiOO!")
    }
}

两者都工作正常，但是例如，当我完成接受协议或接受位置时，第一次出现类似的情况运行应用程序...它将在 [=34 中将 isNewUser 设置为 false =].所以只有一件事我卡住了，我怎样才能重新启动应用程序或将 rootViewController 切换到 MainView()？？

更新： RestartApp，当我点击 "Complete" 按钮时没有运气，没有 UITabBarControl 并且在我杀死应用程序并再次打开之前不会调用 MainView，它工作:( 下面是我的完整代码：

在 SceneDelegate 中：

var versioncheck = "1.0.0.0"

class SceneDelegate: UIResponder, UIWindowSceneDelegate, RestartApp {

    var window: UIWindow?

    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        sceneRestore()
        guard let windowScene = (scene as? UIWindowScene) else { return }
        window = UIWindow(windowScene: windowScene)
        window?.makeKeyAndVisible()
        window?.backgroundColor = UIColor(named: "Main Background")
        restartApp()
    }
    func restartApp() {
        if !UserDefaults.standard.bool(forKey: "New User") {UserDefaults.standard.set(true, forKey: "New User")}
        let isNewUser = UserDefaults.standard.bool(forKey: "New User")
        print(isNewUser) // It will keep say "true" even change to false in UserDefault
        if isNewUser == true {
            window?.rootViewController = ViewController()
        } else if versioncheck != "1.0.0.0" {
            window?.rootViewController = NewUpdate()
        } else {
            window?.rootViewController = MainView()
        }
    }
}

ViewController

protocol RestartApp {
    func restartApp()
}
class ViewController: UIViewController {
    var delegate: RestartApp?
    override func viewDidLoad() {
        super.viewDidLoad()
        welcomePage()
    }
}

当我点击"Complete"按钮时，它会调用：

@objc func welcomeChangeGoToMain () {
    UserDefaults.standard.set(false, forKey: "New User")
    print(UserDefaults.standard.bool(forKey: "New User")) //It said "false"
    welcomeTitle.removeFromSuperview()
    welcomeSubline.removeFromSuperview()
    welcomeNext.removeFromSuperview()
    welcomeRequest.removeFromSuperview()
    self.delegate?.restartApp()
}

Answer 1

您可以创建一个委托协议，只要 isNewUser 值发生变化就会调用它，并在场景中调用它的委托函数 class 以便根据该值呈现视图控制器。喜欢下面：

在你里面 SceneDelegate class :

 // don't forget to assign the RestartApp Delegate here
class SceneDelegate: UIResponder, UIWindowSceneDelegate, RestartApp {

    var window: UIWindow?

    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = (scene as? UIWindowScene) else { return }
    window = UIWindow(windowScene: windowScene)
    window?.makeKeyAndVisible()
    restartApp()
}

并在 sceneDelegate 中创建 restartApp 函数

    func restartApp() {
        let isNewUser = UserDefaults.standard.bool(forKey: "Key")
        if isNewUser == true {
           window?.rootViewController = ViewController()
        } else {
           window?.rootViewController = ViewController2()
        }
}

在您希望重启函数被调用的最后创建协议，它的委托调用如下所示：

protocol RestartApp {
  func restartApp()
}

class ViewController2: UIViewController {

var delegate: RestartApp?

override func viewDidLoad() {
    super.viewDidLoad()
    UserDefaults.standard.set(true, forKey: "Key")
    view.backgroundColor = .yellow
    print("VC2")
    self.delegate?.restartApp() // this should be called wherever you want to restart the app ( inside an action or a function depends on your need )
}

}

总而言之，这里发生了什么，应用程序启动它调用 SceneDelegate class 中的 willConnectTo 函数，这个调用重新启动应用程序并根据 IsNewUser 中保存的最后一个值调用 VC ，然后在你的内部 VC 每次调用 self.delegate.restartApp() 时，它都会调用 SceneDelegate 中的重启函数，并根据你的 isNewUser 值调用 VC 。

更改 ViewController 并重新启动应用程序

Change the ViewController and restart app

ios

swift

class

uiviewcontroller

viewcontroller