如何用swift 2.0播放背景音乐？

Question

嗨我是swift和ios开发的新手.我的代码一直在运行,直到我更新到Swift 2.0,我使用了swift迁移工具,但我仍然无法弄清楚如何对代码进行排序和修复.请帮忙!

import AVFoundation

var backgroundMusicP: AVAudioPlayer!

func playBackgroundMusic(filename: String) {
    let url = NSBundle.mainBundle().URLForResource(
        filename, withExtension: nil)
    if (url == nil) {
        print("Could not find file: \(filename)")
        return
    }

    var error: NSError?

    do {

        backgroundMusicP = try AVAudioPlayer(contentsOfURL: url!)
    } catch {

        backgroundMusicP == nil
    }
    if backgroundMusicP == nil {
        print("Could not create audio player: \(error)")
        return
    }

    backgroundMusicP.numberOfLoops = -1
    backgroundMusicP.prepareToPlay()
    backgroundMusicP.play()
}

Answer 1

更新了swift 2.0的功能:

import AVFoundation

var backgroundMusicPlayer = AVAudioPlayer()

func playBackgroundMusic(filename: String) {
    let url = NSBundle.mainBundle().URLForResource(filename, withExtension: nil)
    guard let newURL = url else {
        print("Could not find file: \(filename)")
        return
    }
    do {
        backgroundMusicPlayer = try AVAudioPlayer(contentsOfURL: newURL)
        backgroundMusicPlayer.numberOfLoops = -1
        backgroundMusicPlayer.prepareToPlay()
        backgroundMusicPlayer.play()
    } catch let error as NSError {
        print(error.description)
    }
}

用这种方式:

playBackgroundMusic("yourFileName.mp3")