无法播放声音文件Swift4

Question

我正在尝试在我的应用程序中播放简单的.wav文件。代码如下：

func alarmSound() {
    var player: AVAudioPlayer?
    guard let path = Bundle.main.path(forResource: "emergency021", ofType: "wav") else {
        print("Can't find audio file")
        return
    }

    let url = URL(fileURLWithPath: path)

    do {
        player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileType.wav.rawValue)
        if let prepare = player?.prepareToPlay() {
            print("Player prepared: \(prepare)")
        }
        player?.volume = 1.0
        player?.play()
    } catch {
        print("Playing sound error: \(error)")
    }
}

一切正常，文件在包里，url没问题，播放器准备好了，但是..没有任何声音。我已经尝试了.mp3文件-同样的结果。有什么想法吗，怎么了？

Answer 1

当我将其上移到ViewController all works时，问题是在函数体中本地声明player: AVAudioPlayer。