注銷后更改 rootviewcontroller

Question

我已經使用 SceneDelegate 在登錄操作后更改 rootviewcontroller。 ?它工作正常，但當我注銷時，我無法再次執行導航。

這是我的 Scenekit 代碼：

 let status = UserDefaults.standard.bool(forKey: UserDefaultKeys.status)
          var rootVC : UIViewController?

          if(status == true){
            rootVC = UIStoryboard(name: AppStoryBoardName.main, bundle: nil).instantiateViewController(withIdentifier: TabBarViewController.className) as? TabBarViewController
          }else{
            rootVC = UIStoryboard(name: AppStoryBoardName.main, bundle: nil).instantiateViewController(withIdentifier: LoginViewController.className) as? LoginViewController
          }

          guard let root = rootVC else {return }
          let nav = UINavigationController(rootViewController: root)
          window?.rootViewController = nav

我的注銷代碼：

appUserDefaults.set(false, forKey: UserDefaultKeys.status)
                                             appUserDefaults.synchronize()
            let loginVC = self.storyboard?.instantiateViewController(withIdentifier: LoginViewController.className) as? LoginViewController
            let window = UIApplication.shared.windows.first
            window?.rootViewController = loginVC

我的登錄按鈕操作：（注銷操作后不起作用）

guard let controller = self.storyboard?.instantiateViewController(withIdentifier: VerificationViewController.className) as? VerificationViewController else { return }
    controller.mobile = phoneTextField.text ?? ""
    self.navigationController?.pushViewController(controller, animated: true)

Answer 1

它不起作用，因為注銷按鈕操作和sceneKit中的視圖控制器層次結構不一致。 在sceneKit 代碼中，您將LoginViewController嵌入到導航控制器中，然后將導航控制器指定為Windows 根視圖控制器。

let status = UserDefaults.standard.bool(forKey: UserDefaultKeys.status)
var rootVC : UIViewController?

if(status == true){
    rootVC = UIStoryboard(name: AppStoryBoardName.main, bundle: nil).instantiateViewController(withIdentifier: TabBarViewController.className) as? TabBarViewController
} else{
    rootVC = UIStoryboard(name: AppStoryBoardName.main, bundle: nil).instantiateViewController(withIdentifier: LoginViewController.className) as? LoginViewController
}

guard let root = rootVC else {return }

// Embedding the specific controller in navigation controller and assigning navigation controller as windows root.

let nav = UINavigationController(rootViewController: root)
window?.rootViewController = nav

在這種情況下，您將在LoginViewController擁有導航控制器，並且登錄按鈕操作完美無缺，即

self.navigationController?.pushViewController(controller, animated: true)

但是在注銷時，您只需將您的LoginViewController分配為 Windows 根，即

appUserDefaults.set(false, forKey: UserDefaultKeys.status) appUserDefaults.synchronize()
let loginVC = self.storyboard?.instantiateViewController(withIdentifier: LoginViewController.className) as? LoginViewController
let window = UIApplication.shared.windows.first

// loginVC is not embedded in Navigation Controller

window?.rootViewController = loginVC

在上述轉換之后， LoginViewController將不會導航控制器，因此在登錄按鈕操作中 pushViewController 的可選鏈接將失敗，即

self.navigationController?.pushViewController(controller, animated: true)

通過在 Navigation Controller 中嵌入LoginViewController來保持一致，即使在注銷時，將注銷操作代碼更新為：

appUserDefaults.set(false, forKey: UserDefaultKeys.status) appUserDefaults.synchronize()
let loginVC = self.storyboard?.instantiateViewController(withIdentifier: LoginViewController.className) as? LoginViewController
let window = UIApplication.shared.windows.first

// Embed loginVC in Navigation Controller and assign the Navigation Controller as windows root
let nav = UINavigationController(rootViewController: loginVC)
window?.rootViewController = nav