c_rath的答案基本上是正确的，但是您无需将视图控制器设为根视图控制器。实际上，即使从App
Delegate，您也可以在导航堆栈的顶视图和任何其他视图控制器之间触发选择。例如，要推送情节提要视图控制器，您可以执行以下操作：

Swift 3.0及更高版本

// Access the storyboard and fetch an instance of the view controller
let storyboard = UIStoryboard(name: "Main", bundle: nil);
let viewController: MainViewController = storyboard.instantiateViewController(withIdentifier: "ViewController") as! MainViewController;

// Then push that view controller onto the navigation stack
let rootViewController = self.window!.rootViewController as! UINavigationController;
rootViewController.pushViewController(viewController, animated: true);

Swift 2.0及更早版本

// Access the storyboard and fetch an instance of the view controller
var storyboard = UIStoryboard(name: "Main", bundle: nil)
var viewController: MainViewController = storyboard.instantiateViewControllerWithIdentifier("ViewController") as MainViewController

// Then push that view controller onto the navigation stack
var rootViewController = self.window!.rootViewController as UINavigationController
rootViewController.pushViewController(viewController, animated: true)