从App Delegate swift执行Segue

Question

我需要从app delegate启动一个视图控制器.

在您在视图控制器之间执行segue的方式.

我有一个if语句,如果true需要显示一个视图控制器,这是在app委托中.

我如何从应用代表执行此操作？

Answer 1

c_rath的答案大多是正确的,但您不需要将视图控制器设置为根视图控制器.实际上,您甚至可以从App Delegate触发导航堆栈顶视图和任何其他视图控制器之间的segue.例如,要推送故事板视图控制器,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和更早版本

// 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)

Answer 2

如果你想使用segue identifier,你可以使用Swift 2.2.

self.window?.rootViewController!.performSegueWithIdentifier("YOUR SEGUE IDENTIFIER", sender: nil)

对于Swift 3.1:

self.window?.rootViewController!.performSegue(withIdentifier: "YOUR SEGUE IDENTIFIER", sender: nil)