How to call method from ViewController in GameScene

Question

I have a method that has a custom segue in my viewController that looks like this:

func gameOver() {
    performSegueWithIdentifier(\"GameOver\", sender: nil         


        

Answer 1

I don't know if this is still relevant, but I would like to present you a solution to this problem.

As you can see here Swift iOS: Perform a Segue from an Instance in a ViewController to another ViewController I had the exact same problem some time ago, which I managed to fix using Protocols.

The problem is, that you can call the "performSegueWithIdentifier("GameOver", sender: nil)" only in your GameViewController Class, but you would like to execute it from your Gamescene.

Therefor you create in your GameScene a protocol like this:

@objc protocol GameOverDelegate {
  func gameOverDelegateFunc()
}

and a variable for the delegate in the Gamescene:

var gamescene_delegate : GameOverDelegate?

in your GameViewController Class you have to add the delegate in the class definition

class GameViewController: UIViewController, GameOverDelegate {
...
}

and set the delegate of the scene in the viewDidLoad function of your GameViewController to self:

scene.gamescene_delegate = self

The last step is to implement the gameOverDelegateFunc() function in your GameViewController:

func gameOverDelegateFunc() {
   self.performSegueWithIdentifier("GameOver", sender: nil)
}

This is all you have to do.

Whenever you want to perform this Segue in your GameScene you just have to call the function through the delegate like this:

gamescene_delegate?.gameOverDelegateFunc()

I hope that everything is clear and I could help,

Regards, Phil

Answer 2

I have done by create protocol, I have 3 game scene (GameScene, GamePlayScene, GameEndScene) and one game controller (GameViewController)

first create gameProtocol

protocol GameDelegate {
 func gameOver()
}

implement protocol in GameViewController

class GameViewController: UIViewController, GameDelegate {
override func viewDidLoad() {
 super.viewDidLoad()
 let scene = GameScene(size: skView.bounds.size)
        scene.scaleMode = .AspectFill
        scene.delegate = self
 }

 // MARK: Game Delegate
 func gameOver() {
    self.performSegueWithIdentifier("yoursegue", sender: self)
 }
}

put delegate property in GameScene class

class GameScene: SKScene {
 var delegate: GameDelegate?

 // call GamePlayScene and put delegate property
 func redirectToPlay() {
        let transition = SKTransition.pushWithDirection(SKTransitionDirection.Left, duration: 1.0)
        let menuScene = GamePlayScene(size: size)
         menuScene.delegate = self.delegate
        self.view?.presentScene(menuScene, transition: transition)
   }
}

and put protocol in GamePlayScene too

class GamePlayScene: SKScene {
     var delegate: GameDelegate?

     // call GameEndScene and put delegate property
     func gameScore() {
            let transition = SKTransition.pushWithDirection(SKTransitionDirection.Left, duration: 1.0)
            let menuScene = GameEndScene(size: size)
             menuScene.delegate = self.delegate
            self.view?.presentScene(menuScene, transition: transition)
       }
    }

and last, put delegate property and call gameOver function

class GameEndScene: SKScene {
     var delegate: GameDelegate?

     init(size: CGSize) {
      // call gameOver function
      self.delegate?.gameOver()
     }
   }

Hope that work and can help you

Sincerely, Donny

Answer 3

the reason this doesnt work is that you are creating a NEW instance of GameViewController and then you're calling gameOver on that. What you really want to do is reference your existing GameViewController

theres a few ways to do this, I'll give you one example.

add a viewController property to your GameScene class

class GameScene {

    // we need to make sure to set this when we create our GameScene
    var viewController: GameViewController!

in your GameViewController file

// after GameScene is instantiated
gameScene.viewController = self

now we have a reference to viewController, lets use it in our GameScene class

// somewhere in GameScene
self.viewController.gameOver()

Answer 4

I don't have enough rep to reply to your last comment, but if you're still getting that error, that's because you haven't given that segue a name (or identifier) yet in Interface Builder!

When you click and drag to draw segues between view controllers in Interface Builder, you can select each transition by the circle icon that appears in the center of the segue lines and give it an 'identifier'. Then, when you call performSegueWithIdentifier, it should work!

This is what the circular icon might look like, depending on the type of segue:

If you're a little unsure of segues, check out this tutorial or this one!