AVAudioPlayer批量加载音频，给定现有路径

Question

我正在尝试加载要设置到viewDidLoad函数内不同按钮的音频。但是，我的应用程序崩溃了这个错误：

  

线程1：致命错误：在展开时出乎意料地发现nil   可选值

override func viewDidLoad() {
    annotateKeys()
    print(constructedArrayOfNotes)


    for key in constructedArrayOfNotes {
        let path = Bundle.main.path(forResource: key, ofType: "mp3")
        do {
            try player = AVAudioPlayer(contentsOf: URL(fileURLWithPath: path!))
            player.prepareToPlay()
            audioPlayers.append(player)
        } catch {
            print("error")
        }

    }

annotate函数构造constructedArrayOfNotes。

的数组

音频文件的名称是“PIANO_C3.mp3”。

这是annotateKeys函数

func annotateKeys() {
    for index in 0...11 {
        constructedArrayOfNotes[index] = "PIANO_" + arrayOfNotes[index] + String(leftSideOfPiano)
    }
    for index in 12...23 {
        constructedArrayOfNotes[index] = "PIANO_" + arrayOfNotes[index] + String(rightSideOfPiano)
    }
}

这就是音频文件的样子：

我不确定我做错了什么，但我猜测路径不正确或Xcode无法找到音频文件。

任何帮助都将不胜感激。

这是更多代码：

var audioPlayers = [AVAudioPlayer]()

var player = AVAudioPlayer()




// An array with notes C through B is sequenced twice in order to
// traverse the left and right keyboard.
let arrayOfNotes = ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"]

var constructedArrayOfNotes = ["","","","","","","","","","","","","","","","","","","","","","","",""]

Answer 1

这是因为path在某些时候将为零，这意味着您的密钥设置不正确。用这个替换你的功能

 for key in constructedArrayOfNotes {
        if let path = Bundle.main.path(forResource: key, ofType: "mp3") {
        do {
            try player = AVAudioPlayer(contentsOf: URL(fileURLWithPath: path))
            player.prepareToPlay()
            audioPlayers.append(player)
        } catch {
            print("error")
        }
      }
    }

看看哪个键没有播放。