无法使用Xcode 8和Swift 3以编程方式在SpriteKit中触发segue

Question

I'm making a game in Xcode 8 using SpriteKit and have been having a very difficult time programmatically triggering a segue. I have gone into "Main.storyboard" and made a segue between my "GameViewController" and "MenuViewController" given it the identifier "toMenu".

Within my GameScene.swift file I have added the following code to the update function.

override func update(_ currentTime: TimeInterval) {
    // Called before each frame is rendered

    if gameIsRunning == false{
        score = 0
        performSegue(withIdentifier: "toMenu", sender: self)
    }
    }

My goal is for the segue to trigger whenever gameIsRunning is false. However, I got the following error:

Use of unresolved identifier 'performSegue'

This is odd because performSegue is a declaration according to the API Reference .

I tried this solution by putting the following code into "GameScene.swift"

override func update(_ currentTime: TimeInterval) {
    // Called before each frame is rendered

    if gameIsRunning == false{
        score = 0
        GameScene(MenuViewController, animated: true, completion: nil)
    }

and I got this error:

Type of expression is ambiguous without more context

I found this solution very confusing but I following along anyways. I had already done step 1, so as stated in step 2, I put the following code at the bottom of "GameViewController.swift"

func goToDifferentView() {

self.performSegue(withIdentifier: "toMenu", sender: self)

}

and didn't get an error! Then I added this code to "GameViewController.swift" as instructed in step 3 of the solution

    override func viewDidLoad() {
    super.viewDidLoad()

    NotificationCenter.default.addObserver(self, selector: #selector(goToDifferentView), name: NSNotification.Name(rawValue: "toMenu"), object: nil)

Then I did step 4 of the solution so I put the following code into "MenuViewController.swift"

    override func viewDidLoad() {
    super.viewDidLoad()

    NotificationCenter.default.post(NSNotification(name: NSNotification.Name(rawValue: "toMenu"), object: nil) as Notification)

I then put the following code into my "GameScene.swift" file to actually call the function.

    override func update(_ currentTime: TimeInterval) {
    // Called before each frame is rendered

    if gameIsRunning == false{
        score = 0
        GameViewController().goToDifferentView()
    }

I then ran my game on my iPhone and everything went well until I get to the part of the game where gameIsRunning turns to false. Instead of the segue doing its thing, I got the following error:

Thread 1: Signal SIGABRT

I've gotten this error several times and it's always been that I have something hooked up incorrectly in "Main.storyboard". However, this an incredibly simple game and everything looks normal. I also didn't get this error until adding the code that I just showed you. I have confirmed several times that the segue has the identifier "toMenu". I have absolutely no clue why the segue won't work and why my Attemp #3 is causing a SIGABRT error.

Answer 1

Since you are trying to trigger this segue in the update() function, it's being called many times per second. Try the following code and it should work.

override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered

if gameIsRunning == false{
    score = 0
    gameIsRunning = true
   NotificationCenter.default.post(NSNotification(name: NSNotification.Name(rawValue: "toMenu"), object: nil) as Notification)
}

If you were to place print("update") in your if statement you would see what I mean. Setting the gameIsRunning bool to true inside your if will insure it only gets called once.