iOS - 在更改根視圖控制器時獲取黑色視圖

Question

我試圖在按鈕從ViewController1切換到ViewController2時更改根視圖控制器，反之亦然。問題是我設置我的第二個視圖控制器作爲根視圖控制器後，我越來越黑屏。我附上我的代碼。

我AppDelegate.swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 
     // Override point for customization after application launch. 
     self.window = UIWindow(frame: UIScreen.mainScreen().bounds) 
     let storyBoard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) 
     let vc1 = storyBoard.instantiateViewControllerWithIdentifier("VC1") as! VC1 
     let nc = UINavigationController(rootViewController: vc1) 
     self.window?.rootViewController = nc 
     self.window?.makeKeyAndVisible() 

     return true 
    } 

第一個視圖控制器（VC1.swift）

class VC1: UIViewController { 

    override func viewDidLoad() { 
     super.viewDidLoad() 
    } 

    deinit { 
     print("Deinit of VC1") 
    } 

    @IBAction func btnTapped(sender: AnyObject) { 
     let window = UIApplication.sharedApplication().windows[0] 
     let rootNavigationControl = window.rootViewController as! UINavigationController 

     let storyBoard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) 
     let vc2 = storyBoard.instantiateViewControllerWithIdentifier("VC2") as! VC2 
     let nc = UINavigationController(rootViewController: vc2) 

     rootNavigationControl.presentViewController(nc, animated: true) {() -> Void in 
      // ------- Becomes black screen here ---------- 
      rootNavigationControl.viewControllers = [vc2] 
     } 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
    } 
} 

第二個視圖控制器（VC2.swift）

class VC2: UIViewController { 

    override func viewDidLoad() { 
     super.viewDidLoad() 
    } 

    deinit { 
     print("Deinit of VC2") 
    } 

    @IBAction func btnTapped(sender: AnyObject) { 
     let window = UIApplication.sharedApplication().windows[0] 
     let rootNavigationControl = window.rootViewController as! UINavigationController 

     let storyBoard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) 
     let vc1 = storyBoard.instantiateViewControllerWithIdentifier("VC1") as! VC1 
     let nc = UINavigationController(rootViewController: vc1) 

     rootNavigationControl.presentViewController(nc, animated: true) {() -> Void in 
      rootNavigationControl.viewControllers = [vc1] 
     } 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
    } 
} 

請能有人幫助我找出問題所在。 在此先感謝您的幫助。

Answer 1

我會做這樣的事情：

AppDelegate.swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool 
{ 
    let storyBoard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) 
    let vc1 = storyBoard.instantiateViewControllerWithIdentifier("VC1") 
    let nc = UINavigationController(rootViewController: vc1) 
    self.window?.rootViewController = nc 

    return true 
} 

VC1.swift

class VC1: UIViewController 
{ 

    @IBAction func btnTapped(sender: AnyObject) 
    { 
     if let vc2 = self.storyboard?.instantiateViewControllerWithIdentifier("VC2") 
     { 
      self.navigationController?.pushViewController(vc2, animated: true) 
     } 
    } 
} 

VC2.swift

class VC2: UIViewController 
{ 

    @IBAction func btnTapped(sender: AnyObject) 
    { 
     if let vc1 = self.storyboard?.instantiateViewControllerWithIdentifier("VC1") 
     { 
      self.navigationController?.pushViewController(vc1, animated: true) 
     } 
    } 
}