ios - 从应用程序委托(delegate)访问导航 Controller

Question

我想从 appDelegate 访问一个嵌入了 UINavigation Controller 的 View Controller 。

我该怎么做，我知道我可以直接访问该 View Controller ，但在这种情况下导航栏不会出现，因此这不是我想要的。

我已经尝试了下面找到的代码，但它会提示警告并出现黑屏。

var storyboard1 = UIStoryboard(name: "Main", bundle: nil)
        var viewController: ExamNav_ViewController = storyboard1.instantiateViewControllerWithIdentifier("ExamNav_ViewController") as! ExamNav_ViewController
        var rootViewController = self.window!.rootViewController as! UINavigationController
   // rootViewController.pushViewController(viewController, animated: true)
    rootViewController.presentViewController(viewController, animated: true, completion: nil)

警告是:尝试在 UINavigationController 上呈现 PlayMyWay.ExamNav_ViewController:0x14fd19b50:0x14fd13a90 其 View 不在窗口层次结构中!

Answer 1

window = UIWindow(frame: UIScreen.mainScreen().bounds)
let navController: UINavigationController = UIStoryboard(name: "Main", bundle:nil).instantiateViewControllerWithIdentifier("provaNavController") as UINavigationController
window?.rootViewController = navController
window?.makeKeyAndVisible()

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