AVAudioSession重新激活问题

我收到以下错误：

[0x19bf89310] AVAudioSession.mm:646： - [AVAudioSession setActive：withOptions：error：]：停用已运行I / O的音频会话 . 在停用音频会话之前，应停止或暂停所有I / O.

我已经阅读了这篇文章：

• iOS8 AVAudioSession setActive error

但那里的解决方案并没有解决我的问题 . 这是：

• 小应用程序（游戏）
  在AudioHelper.swift中处理

• 音频背景音乐

• 附加'blip'声音播放 SKActino.playSoundFile

再 生产环境

• 开始游戏（背景音乐开始播放）

• 近距离比赛（音乐停止）

• 重启游戏（音乐重新开始）
  出现

• 错误

• SKAction.playSoundFile don 't always work anymore (some do, some don' t）

我的音频处理代码（又名AudioHelper.swift）

class AudioHelper: NSObject, AVAudioPlayerDelegate {
    var player : AVAudioPlayer?

    class var defaultHelper : AudioHelper {
        struct Static {
            static let instance : AudioHelper = AudioHelper()
        }

        return Static.instance
    }

    override init() {
        super.init()
    }

    func initializeAudio() {
        var url = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("sound_float", ofType: ".mp3")!)
        self.player = AVAudioPlayer(contentsOfURL: url, error: nil)
        self.player?.numberOfLoops = -1
        self.player?.play()
    }

    func stopAudio() {
        self.player?.stop()
        self.player?.prepareToPlay()
        AVAudioSession.sharedInstance().setActive(false, error: nil)
    }

    func startAudio() {
        AVAudioSession.sharedInstance().setActive(true, error: nil)
        self.player?.play()
    }

    func audioPlayerDidFinishPlaying(player: AVAudioPlayer!, successfully flag: Bool) {
        self.stopAudio()
    }
}

我正在初始化和暂停并开始 AppDelegate

class AppDelegate: UIResponder, UIApplicationDelegate {


    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        AudioHelper.defaultHelper.initializeAudio()
        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.
        AudioHelper.defaultHelper.stopAudio()
    }

    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.
        AudioHelper.defaultHelper.startAudio()
    }
}

我哪里错了？