以编程方式设置 rootViewController 不起作用，仅在 Xcode 11 中从情节提要中选择初始视图控制器答案

【问题标题】：Set rootViewController programmatically not working, picking initial view controller from storyboard only in Xcode 11以编程方式设置 rootViewController 不起作用，仅在 Xcode 11 中从情节提要中选择初始视图控制器
【发布时间】：2020-01-02 12:38:50
【问题描述】：

尝试以编程方式更改根视图控制器，最初在情节提要中检查初始视图控制器。每次打开相同的 viewController 时，它在情节提要中设置为 initialViewController。请指导。在下面分享到目前为止尝试过的代码：

let isLoggedIn = UserDefaults.standard.bool(forKey: kIsLoggedIn)
        if isLoggedIn{
            //Welcome Screen for Touch ID
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
           // let rootVC = storyboard.instantiateViewController(withIdentifier: "WelcomeViewController") as! WelcomeViewController
            let rootVC = storyboard.instantiateViewController(withIdentifier: "DashboardVC") as! DashboardVC
            setRoot(rootVC: rootVC)
        }
        else{
            //Login Screen
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let rootVC = storyboard.instantiateViewController(withIdentifier: "RegisterViewController") as! RegisterViewController
            setRoot(rootVC: rootVC)
        }

func setRoot(rootVC: UIViewController){
    let navController = UINavigationController.init(rootViewController: rootVC)
    navController.isNavigationBarHidden = true
    //if let window = self.window{
        window?.rootViewController = rootVC
        window?.makeKeyAndVisible()
    //}
}

其次，尝试更改 rootViewController 并尝试在登录后添加 MFSideMenu 但无法快速运行。请在下面找到它的代码：

 func loadDashBoard(storyboard : UIStoryboard){
    let vc = storyboard.instantiateViewController(withIdentifier: "MenuNavigationController")
    let sideMenuVC = storyboard.instantiateViewController(withIdentifier: "SideMenuViewController") as! SideMenuViewController
    let container : MFSideMenuContainerViewController = MFSideMenuContainerViewController.container(withCenter: vc, leftMenuViewController: sideMenuVC, rightMenuViewController: nil)
    let navController = UINavigationController.init(rootViewController: container)
    navController.isNavigationBarHidden = true

        window?.rootViewController = navController
        window?.makeKeyAndVisible()
    }

以上所有编写的代码都在AppDelegate中。

【问题讨论】：

应用代理在 Xcode 11 中没有窗口或根视图控制器。它是场景代理。

标签： swift xcode11 side-menu rootviewcontroller uiscenedelegate

【解决方案1】：

通过更多的谷歌得到答案，我的意思是stackoverflow。

class SceneDelegate: UIResponder, UIWindowSceneDelegate {

var window: UIWindow?
let storyboard = UIStoryboard(name: "Main", bundle: nil)

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
  guard let windowScene = scene as? UIWindowScene else { return }
  let vc = storyboard.instantiateViewController (withIdentifier: "Primary") as! ViewController
  window = UIWindow(windowScene: windowScene)
  window?.rootViewController = vc
  window?.makeKeyAndVisible()
}

SceneDelegate 用于此目的，因为 iOS 13 不是 AppDelegate。这是链接SceneDelegate example

【讨论】：