Cannot stop background music from within Game Scenes, Swift 3/Spritekit

问题

On XCODE 8/Swift 3 and Spritekit, i am playing background music (a 5 minute song), calling it from GameViewController's ViewDidLoad (from the parent of all the scenes, not from a specific GameScene), as I want it to play throughout scene changes without stopping. This happens without a problem.

But my problem is, how do i stop the background music at will, when I am inside a scene? Say when user gets to a specific score on the game on the 3rd scene? As i cannot access the methods of the parent file. Here is the code I used to call the music to play:

class GameViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    var audioPlayer = AVAudioPlayer()

    do {
        audioPlayer =  try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: Bundle.main.path(forResource: "music", ofType: "mp3")!))
        audioPlayer.prepareToPlay()

    } catch {

        print (error)
    }
    audioPlayer.play()

Many thanks for any help

回答1:

Why not create a music helper class that you can access from anywhere. Either the singleton way or a class with static methods. This should also make your code cleaner and easier to manage.

I would also split the setup method and the play method so that you do not set up the player each time you play the file.

e.g Singleton

class MusicManager {

    static let shared = MusicManager()

    var audioPlayer = AVAudioPlayer()


    private init() { } // private singleton init


    func setup() {
         do {
            audioPlayer =  try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: Bundle.main.path(forResource: "music", ofType: "mp3")!))
             audioPlayer.prepareToPlay()

        } catch {
           print (error)
        }
    }


    func play() {
        audioPlayer.play()
    }

    func stop() {
        audioPlayer.stop()
        audioPlayer.currentTime = 0 // I usually reset the song when I stop it. To pause it create another method and call the pause() method on the audioPlayer.
        audioPlayer.prepareToPlay()
    }
}

When your project launches just call the setup method