如何在Swift中初始化AVAudioPlayer

Question

我有這個文件，並希望在另一個類中使用此文件，但這不起作用。我認爲這是因爲我沒有在這個文件中初始化AVAudioPlayer，所以我解決了這個問題，但是出現了一條消息，說"Call can throw, but it is not marked with 'try' and the error is not handled"我的實現不成功。我不知道如何處理這個問題。你能指出初始化有什麼問題，並提供一些可用的代碼。提前致謝。

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

我推薦使用這種方式init你管理器，它不必是AVAudioPlayer的子類。

 
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()