如何在 Swift 中初始化 AVAudioPlayer

Question

我有这个文件，想在另一个 class 中使用这个文件，但这不起作用。我假设这是因为我没有在这个文件中初始化 AVAudioPlayer，所以我解决了这个问题，但是出现了一条消息，说 "Call can throw, but it is not marked with 'try' and the error is not handled" 我的实现不成功。我不知道该如何处理。你能指出初始化有什么问题并提供一些有效的代码吗？提前致谢。

class SoundManager: AVAudioPlayer {
var _Sound: AVAudioPlayer!

override init() {
    let url = NSBundle.mainBundle().URLForResource("rain", withExtension: "wav")
    super.init(contentsOfURL: url!)
}

func playSound() {


    if (url == nil) {
        print("Could not find the file \(_Sound)")
    }

    do {
        _Sound = try AVAudioPlayer(contentsOfURL: url!, fileTypeHint: nil)

    }
    catch let error as NSError { print(error.debugDescription)

    }
    if _Sound == nil {
        print("Could not create audio player")
    }
    _Sound.prepareToPlay()
    _Sound.numberOfLoops = -1
    _Sound.play()
}

}

Answer 1

我建议使用这种方式初始化你的管理器，它不必是 AVAudioPlayer 的子类。

class SoundManager {
    var _Sound: AVAudioPlayer!
    var url: NSURL?

    /**
     init with file name

     - parameter fileName: fileName

     - returns: SoundManager
     */
    init(fileName: String) {
        url = NSBundle.mainBundle().URLForResource(fileName, withExtension: "wav")
    }

    func playSound() {
        if (url == nil) {
            print("Could not find the file \(_Sound)")
        }

        do {
            _Sound = try AVAudioPlayer(contentsOfURL: url!, fileTypeHint: nil)

        }
        catch let error as NSError { print(error.debugDescription)

        }
        if _Sound == nil {
            print("Could not create audio player")
        }
        _Sound.prepareToPlay()
        _Sound.numberOfLoops = -1
        _Sound.play()
    }
}

使用 let manager = SoundManager(fileName: "hello") manager.playSound()

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