xcode - 如何仅播放一次声音 SWIFT

Question

我的代码有一个小问题，即在启动应用程序时播放声音。但是，每次我返回第一个屏幕时，都会出现问题，声音会再次播放，而我希望它只播放一次。当菜单屏幕第一次弹出时。

这是我的代码

   var bubbleSound: SystemSoundID!
 bubbleSound = createBubbleSound()
 AudioServicesPlaySystemSound(bubbleSound)

(...)

函数

func createBubbleSound() -> SystemSoundID {
            var soundID: SystemSoundID = 0
    let soundURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), "bubble", "wav", nil)
    AudioServicesCreateSystemSoundID(soundURL, &soundID)
    return soundID

}

Answer 1

您可以像这样定义一个struct (source):

struct MyViewState {
    static var hasPlayedSound = false
}

然后在你的viewDidLoad中:

if(!MyViewState.hasPlayedSound) {
    var bubbleSound: SystemSoundID!
    bubbleSound = createBubbleSound()
    AudioServicesPlaySystemSound(bubbleSound)
    MyViewState.hasPlayedSound = true
}

然后，您可以修改 MyViewState.hasPlayedSound 并允许 UIViewController 如果需要的话再次播放声音。