iOS-更改根视图控制器时获得黑色视图

我试图在点击按钮时将根视图控制器从ViewController1更改为ViewController2，反之亦然。问题是，在我将第二个视图控制器设置为根视图控制器后，我会出现黑屏。随信附上我的密码

我的代表，斯威夫特

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
    }

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
}

第一视图控制器（VC1.swift）

第二视图控制器（VC2.swift）

请有人帮我找出问题所在。

---

提前感谢您的帮助。

我会这样做：

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
    }

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 {

    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()
    }
}

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 {

    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()
    }
}

class VC2: UIViewController 
{

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

---

虽然我同意在iOS中，将VC2推到导航控制器堆栈中更为常见，而且可能是更好的UX，但iOSFresh明确要求将VC1替换为VC2。并不是说VC2会被推到堆栈上。如果您真的想替换视图控制器，我会使用self.navigationController？.setViewControllers（[VC2]，动画：true）而不是self.navigationController？.pushViewController（VC2，动画：true）