ios - 为什么即使在 Storyboard中嵌入导航 Controller 并使用 push segue 后，我的导航 Controller 仍为零？

Question

我已尝试阅读 Stackoverflow 上的几个主题，但我认为我已经实现了所有主题，但仍然无法正常工作。这是我的 Storyboard

所以我隐藏(取消选中)导航栏可见性，如下图所示，因为我想实现我自己的“导航标题”，如上图(右图)所示:

当按下后退按钮时，我使用下面的代码:

self.navigationController?.popViewController(animated: true)

但不幸的是，在我检查之后，导航 Controller 为零，我无法返回到之前的 VC。

我像这样在应用程序委托(delegate)中设置了一些代码，以设置导航。如果用户已经登录，那么它将被导航到 HomeVC(主标签栏)，否则它将被定向到登录序列，就像我上面的 Storyboard一样

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        // to print Local Database Location, uncomment the line below if you want to trace the location of Realm Database / User Default
        // print("Location of Realm Database: \(Realm.Configuration.defaultConfiguration.fileURL)")



        checkHasLoggedInOrNot()




        return true
    }




}

extension AppDelegate {
    // MARK: - Helper Methods

    func checkHasLoggedInOrNot() {
        let userHasLoggedIn = AuthService.shared.hasLoggedIn

        if userHasLoggedIn {
            goToMainTabBar()
        } else {
            goToAuthVC()
        }
    }


}

extension AppDelegate {
    // MARK: - Navigation

    func goToMainTabBar() {
        let storyboard = UIStoryboard(name: StoryBoardName.Main.rawValue, bundle: nil)
        let mainTabBar = storyboard.instantiateViewController(withIdentifier: MainStoryboardData.StoryBoardID.MainTabBar.rawValue)
        window?.rootViewController = mainTabBar
    }

    func goToAuthVC() {
        let storyboard = UIStoryboard(name: StoryBoardName.Auth.rawValue, bundle: nil)
        let authVC = storyboard.instantiateViewController(withIdentifier: AuthStoryboardData.StoryBoardID.AuthVC.rawValue)
        window?.rootViewController = authVC
    }
}

也许问题出在下面的代码上？

func goToAuthVC() {
        let storyboard = UIStoryboard(name: StoryBoardName.Auth.rawValue, bundle: nil)
        let authVC = storyboard.instantiateViewController(withIdentifier: AuthStoryboardData.StoryBoardID.AuthVC.rawValue)
        window?.rootViewController = authVC
    }

因为它指向 AuthVC ？不是导航 Controller ？

这里出了什么问题？

Answer 1

Push/Pop 仅当 window 中有 Navigation stack 时才有可能。

将您的 goToAuthVC 替换为以下 -

func goToAuthVC() {

    let storyboard = UIStoryboard(name: StoryBoardName.Auth.rawValue, bundle: nil)
    let authVC = storyboard.instantiateViewController(withIdentifier: AuthStoryboardData.StoryBoardID.AuthVC.rawValue)
    let navigationController  = UINavigationController(rootViewController: authVC)
    window?.rootViewController = navigationController
    window?.makeKeyAndVisible()

}