swift - AppDelegate 中的动画后不显示 HomeViewController

Question

我试图在启动应用程序时在 AppDelegate 中制作动画。 (来自本教程:http://iosdevtips.co/post/88481653818/twitter-ios-app-bird-zoom-animation)

我想在我的 HomeViewController 上制作 mask

这是我的 AppDelegate

import UIKit
import QuartzCore

@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?
var mask: CALayer?
var imageView: UIImageView?


func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)

    let imageView = UIImageView(frame: self.window!.frame)
    imageView.image = UIImage(named: "portfolioscreen")
    self.window!.addSubview(imageView)

    self.mask = CALayer()
    self.mask!.contents = UIImage(named: "BearLogo.png")!.CGImage
    self.mask!.contentsGravity = kCAGravityResizeAspect
    self.mask!.bounds = CGRect(x: 0, y: 0, width: 100, height: 100)
    self.mask!.anchorPoint = CGPoint(x: 0.5, y: 0.5)
    self.mask!.position = CGPoint(x: imageView.frame.size.width/2, y: imageView.frame.size.height/2)
    imageView.layer.mask = mask
    self.imageView = imageView

    animateMask()

    if(NSUserDefaults.standardUserDefaults().integerForKey("visits") > 0)
    {
        var navigationController = UINavigationController(rootViewController: HomeViewController())
        window?.rootViewController = navigationController
    }
    else
    {
        window?.rootViewController = ViewController()
        NSUserDefaults.standardUserDefaults().setInteger(1, forKey: "visits")
    }
    //window?.makeKeyAndVisible()

    self.window!.backgroundColor = UIColor(red: 70/255, green: 154/255, blue: 233/255, alpha: 1)
    self.window!.makeKeyAndVisible()
    UIApplication.sharedApplication().statusBarHidden = true
    return true

}


func applicationWillResignActive(application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

func applicationDidEnterBackground(application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(application: UIApplication) {
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

func animateMask() {
     let keyFrameAnimation = CAKeyframeAnimation(keyPath: "bounds")
     keyFrameAnimation.delegate = self
     keyFrameAnimation.duration = 1
     keyFrameAnimation.beginTime = CACurrentMediaTime() + 1 //add delay of 1 second
     let initalBounds = NSValue(CGRect: mask!.bounds)
     let secondBounds = NSValue(CGRect: CGRect(x: 0, y: 0, width: 90, height: 90))
     let finalBounds = NSValue(CGRect: CGRect(x: 0, y: 0, width: 1500, height: 1500))
     keyFrameAnimation.values = [initalBounds, secondBounds, finalBounds]
     keyFrameAnimation.keyTimes = [0, 0.3, 1]
     keyFrameAnimation.timingFunctions = [CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut), CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)]
     self.mask!.addAnimation(keyFrameAnimation, forKey: "bounds")
}

override func animationDidStop(anim: CAAnimation!, finished flag: Bool) {
    self.imageView!.layer.mask = nil //remove mask when animation completes

    var homeViewController = HomeViewController(nibName: "HomeViewController", bundle: NSBundle.mainBundle())

    self.window?.rootViewController = homeViewController
    self.window!.makeKeyAndVisible()



}


}

当我启动模拟器时，它崩溃了，并且右下角出现错误。我写错了？

帮助将不胜感激

Answer 1

please put this block of execution in the completionHandler in the animate method and try?

if(NSUserDefaults.standardUserDefaults().integerForKey("visits") > 0)
    {
        var navigationController = UINavigationController(rootViewController: HomeViewController())
        window?.rootViewController = navigationController
    }
    else
    {
        window?.rootViewController = ViewController()
        NSUserDefaults.standardUserDefaults().setInteger(1, forKey: "visits")
    }