Ios 其视图不在窗口层次结构中的LoginViewController！代表

我的目标是检查钥匙链中是否有令牌，如果没有，则只显示登录视图控制器屏幕。现在的问题是，我得到了这个错误。我在AppDelegate.swift中编写了此代码

.LoginViewController:0x7ff59b619820>其视图不在窗口层次结构中

这是密码

   func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

     let keychain = Keychain(server: "https://app.herokuapp.com", protocolType: .HTTPS)

     if ((try? keychain.contains("token")) != nil) {
        showLoginScreen()
     } else {

     }
      return true
     }

    func showLoginScreen() -> Void {
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as! LoginViewController
        let rootViewController = self.window!.rootViewController
        rootViewController?.presentViewController(setViewController, animated: false, completion: nil)
    }

试试这个

在出现之前添加

self.window.makeKeyAndVisible（）

更新

   let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as! LoginViewController
      self.window.makeKeyAndVisible()
    self.window!.rootViewController.presentViewController(setViewController, animated: false, completion: nil)

有关更多信息，请参见

在出现之前添加

self.window.makeKeyAndVisible（）

更新

   let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as! LoginViewController
      self.window.makeKeyAndVisible()
    self.window!.rootViewController.presentViewController(setViewController, animated: false, completion: nil)

---

有关更多信息，请参见

，方法是将视图控制器设置为UINavigationControllers rootviewcontroller，然后将navigationcontroller添加为Windows rootviewcontrollers，以查看下面修改的代码：

func showLoginScreen() -> Void {
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as UIViewController
    let navigationController = UINavigationController(rootViewController: vc)
    self.window!.rootViewController = navigationController
    self.window!.makeKeyAndVisible()
}

如果您想根据登录状态在两个ViewController之间切换，我建议您遵循以下方法：

self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
if LofinStatus == true{
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let vc = mainStoryboard.instantiateViewControllerWithIdentifier("My_Offer") as UIViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.window!.rootViewController = navigationController
    }else{
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Login", bundle: nil)
        let vc = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as UIViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.window!.rootViewController = navigationController
    }
self.window!.makeKeyAndVisible()

注意：在上述代码中，我使用了两个故事板Main和Login

---

它对我非常有效，请尝试一下并告诉我结果。感谢您将视图控制器设置为UINavigationControllers rootviewcontroller，然后将navigationcontroller添加为Windows rootviewcontrollers将起作用查看下面修改的代码：

func showLoginScreen() -> Void {
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as UIViewController
    let navigationController = UINavigationController(rootViewController: vc)
    self.window!.rootViewController = navigationController
    self.window!.makeKeyAndVisible()
}

如果您想根据登录状态在两个ViewController之间切换，我建议您遵循以下方法：

self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
if LofinStatus == true{
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let vc = mainStoryboard.instantiateViewControllerWithIdentifier("My_Offer") as UIViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.window!.rootViewController = navigationController
    }else{
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Login", bundle: nil)
        let vc = mainStoryboard.instantiateViewControllerWithIdentifier("loginView") as UIViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.window!.rootViewController = navigationController
    }
self.window!.makeKeyAndVisible()

注意：在上述代码中，我使用了两个故事板Main和Login 它对我非常有效，试试看，告诉我结果。谢谢