ios - 无法从 AppDelegate 中实例化 rootViewController

Question

我的入职流程(登录/注册)位于 UINavigationController 链之外，但是当登录通过身份验证时，我在 appdelegate 中调用一个方法，该方法应该实例化 rootViewController，然后推送给它。我试过两件事:

上面的代码片段在 appDelegate 中通过一个方法运行，该方法在响应本地通知时被调用，但在本例中不是。

  self.window?.makeKeyAndVisible()
  self.window?.rootViewController?.navigationController?.popToRootViewControllerAnimated(true)

这是我尝试过的另一种方法:

 let rootViewController = self.window?.rootViewController

    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let dashboard = mainStoryboard.instantiateViewControllerWithIdentifier("DashboardViewController") as! DashboardViewController

   rootViewController!.navigationController?.popToViewController(dashboard, animated: true)

这些都不起作用。我做错了什么？

Answer 1

我的登录 View Controller 也存在于我的标签栏 Controller 之外，所以这就是我所做的:

在 appDelegate 中:

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.


    let storyboard  = UIStoryboard(name: "Main", bundle: nil)
    let loginVC = storyboard.instantiateViewControllerWithIdentifier("LoginVC") as! LoginViewController
    self.window?.rootViewController = loginVC
    self.window!.makeKeyAndVisible()


    return true
}

然后我的 loginViewContoller.swift 中有一个方法:

    @IBAction func loginPushed(sender: AnyObject) {


    //other stuff here 

    let mainStoryBoard = UIStoryboard(name: "Main", bundle: nil)
    let tabBarController = UITabBarController()
    let first = mainStoryBoard.instantiateViewControllerWithIdentifier("firstNavController") as! UINavigationController
    let second = mainStoryBoard.instantiateViewControllerWithIdentifier("secondNavController") as! UINavigationController
    let third = mainStoryBoard.instantiateViewControllerWithIdentifier("thirdNavController") as! UINavigationController

    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let controllers = [first, second, third]

    tabBarController.viewControllers = controllers
    appDelegate.window!.rootViewController = tabBarController
    appDelegate.window!.makeKeyAndVisible()

}