无法停止背景音乐（Swift 3、Xcode 8）

Question

我有一个 AVAudioPlayer 在视图加载时运行的实例。来自另一个ViewController 我有一个UISwitch 来停止音乐。我可以从开关接收Bool 并看到它在console 中调用了正确的函数，但我无法让音乐停止播放。我曾尝试停止、暂停和更改音量，但无济于事。当应用程序关闭（双击主页并向上滑动）并且开关状态被关闭时，音乐将不会播放。如果您打开开关，音乐将播放但不会停止。

代码：

var player:AVAudioPlayer = AVAudioPlayer()

let optionDefaults = UserDefaults.standard

override func viewDidLoad() {

    super.viewDidLoad()

    do{

        let audioPath = Bundle.main.path(forResource: "backgroundmusic", ofType: "wav")
        try player = AVAudioPlayer(contentsOf: NSURL(fileURLWithPath: audioPath!) as URL)
        player.volume = 0.2

        if optionDefaults.value(forKey: "musicOn") != nil  {

            let musicOn: Bool = optionDefaults.value(forKey: "musicOn") as! Bool
            if musicOn == false  {

                print("********** Music is off **********")
                player.stop()

            }

            else {

                print("********** Music is On **********")
                player.play()

            }  
        } 
    } catch {
       print("AVPlayer did not initialize")
    }

    player.numberOfLoops = -1
}

********开关代码********

 let optionDefaults = UserDefaults.standard

 @IBOutlet weak var musicOnOff: UISwitch!

 var musicOn : Bool = true

 @IBAction func switchToGame(sender: UIButton) {


    if musicOnOff.isOn{

        musicOn = true
        optionDefaults.set(musicOn, forKey: "musicOn")

    }

    if musicOnOff.isOn == false{

        musicOn = false
        optionDefaults.set(musicOn, forKey: "musicOn")

    }}

override func viewDidLoad() {
    super.viewDidLoad()

if optionDefaults.value(forKey: "musicOn") != nil  {

    let musicOn: Bool = optionDefaults.value(forKey: "musicOn") as! Bool
    if musicOn == false  {

        musicOnOff.isOn = false

    }

    else{

        musicOnOff.isOn  = true

    }
}}

Answer 1

您仅在视图加载完成时播放音乐。如果您想在切换切换时停止并播放，只需在切换切换操作上调用 palyOrStopMusic 方法

var player:AVAudioPlayer = AVAudioPlayer()

let optionDefaults = UserDefaults.standard

override func viewDidLoad() {

super.viewDidLoad()
     playOrStopMusic()
  }

func playOrStopMusic(){
 do{

        let audioPath = Bundle.main.path(forResource: "backgroundmusic", ofType: "wav")
        try player = AVAudioPlayer(contentsOf: NSURL(fileURLWithPath: audioPath!) as URL)
        player.volume = 0.2

        if optionDefaults.value(forKey: "musicOn") != nil  {

            let musicOn: Bool = optionDefaults.value(forKey: "musicOn") as! Bool
            if musicOn == false  {

                print("********** Music is off **********")
                player.stop()

            }

            else {

                print("********** Music is On **********")
                player.play()

            }  
        } 
    } catch {
       print("AVPlayer did not initialize")
    }

    player.numberOfLoops = -1
}

********开关代码********

 let optionDefaults = UserDefaults.standard

 @IBOutlet weak var musicOnOff: UISwitch!

 var musicOn : Bool = true

 @IBAction func switchToGame(sender: UIButton) {


    if musicOnOff.isOn{
        musicOn = true
        optionDefaults.set(musicOn, forKey: "musicOn")
    }else{
        musicOn = false
        optionDefaults.set(musicOn, forKey: "musicOn")
    }

    playOrStopMusic()
}

override func viewDidLoad() {
    super.viewDidLoad()
    playOrStopMusic()
}