ios AVAudioPlayer 不在 Swift 中播放音频

AVAudioPlayer not playing audio in Swift

提问by Kenneth

I have this code in a very simple, single view Swift application in my ViewController:

我在我的一个非常简单的单视图 Swift 应用程序中有此代码ViewController：

var audioPlayer = AVAudioPlayer()

@IBAction func playMyFile(sender: AnyObject) {

    let fileString = NSBundle.mainBundle().pathForResource("audioFile", ofType: "m4a")
    let url = NSURL(fileURLWithPath: fileString)
    var error : NSError?
    audioPlayer = AVAudioPlayer(contentsOfURL: url, error: &error)
    audioPlayer.delegate = self
    audioPlayer.prepareToPlay()
    if (audioPlayer.isEqual(nil)) {
        println("There was an error: (er)")
    } else {
        audioPlayer.play()
        NSLog("working")
    }

I have added import AVFoundationand audioPlayeris a global variable. When I execute the code, it does print "working", so it makes it through without errors but no sound is played. The device is not in silent.

我添加了import AVFoundation并且audioPlayer是一个全局变量。当我执行代码时，它会打印“工作”，因此它可以无错误地通过，但没有播放声音。设备未处于静音状态。

回答by matt

There's so much wrong with your code that Socratic method breaks down; it will probably be easiest just to throw it out and show you:

你的代码有很多错误，以至于苏格拉底方法崩溃了；把它扔掉并展示给你看可能是最简单的：

var player : AVAudioPlayer! = nil // will be Optional, must supply initializer

@IBAction func playMyFile(sender: AnyObject?) {
    let path = NSBundle.mainBundle().pathForResource("audioFile", ofType:"m4a")
    let fileURL = NSURL(fileURLWithPath: path)
    player = AVAudioPlayer(contentsOfURL: fileURL, error: nil)
    player.prepareToPlay()
    player.delegate = self
    player.play()
}

I have not bothered to do any error checking, but the upside is you'll crash if there's a problem.

我没有费心做任何错误检查，但好处是如果出现问题你会崩溃。

One final point, which may or may not be relevant: not every m4afile is playable. A highly compressed file, for example, can fail silently (pun intended).

最后一点，可能相关也可能不相关：并非每个m4a文件都可以播放。例如，高度压缩的文件可能会静默失败（双关语）。

回答by iHolm

Important that AvPlayer is class member and not in the given function, else it goes out of scope... :)

重要的是 AvPlayer 是类成员而不是在给定的函数中，否则它超出范围...... :)

回答by bpolat

Here is a working snippet from my swift project. Replace "audiofile" by your file name.

这是我的 swift 项目中的一个工作片段。用您的文件名替换“audiofile”。

    var audioPlayer = AVAudioPlayer()
    let audioPath = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("audiofile", ofType: "mp3"))
    audioPlayer = AVAudioPlayer(contentsOfURL: audioPath, error: nil)
    audioPlayer.delegate = self
    audioPlayer.prepareToPlay()
    audioPlayer.play()

You can download fully functional Swift Audio Player application source code from here https://github.com/bpolat/Music-Player

您可以从这里下载功能齐全的 Swift 音频播放器应用程序源代码 https://github.com/bpolat/Music-Player

回答by Anonymous

for some reason (probably a bug) Xcode can't play certain music files in the .m4a and the .mp3 format I would recommend changing them all to .wav files to get it to play

出于某种原因（可能是错误）Xcode 无法播放 .m4a 和 .mp3 格式的某些音乐文件我建议将它们全部更改为 .wav 文件以使其播放

//top of your class
var audioPlayer = AVAudioPlayer

//where you want to play your sound
let Sound = NSURL(fileURLWithPath: Bundle.main.path(forResource: "sound", ofType: "wav")!)
    do {
        audioPlayer = try AVAudioPlayer(contentsOf: Sound as URL)
        audioPlayer.prepareToPlay()
    } catch {
        print("Problem in getting File")
    }
    audioPlayer.play()

回答by Aleksey Shevchenko

Based on @matt answer but little bit detailed 'cause original answer did not completely satisfied me.

基于@matt 答案，但有点详细，因为原始答案并没有让我完全满意。

import AVFoundation

class YourController: UIViewController {

  private var player : AVAudioPlayer?

  override func viewDidLoad() {
     super.viewDidLoad()

     prepareAudioPlayer()
  }

  @IBAction func playAudio() {

      player?.play()
  }
}

extension YourController: AVAudioPlayerDelegate {}

private extension YourController {

    func prepareAudioPlayer() {

        guard let path = Bundle.main.path(forResource: "you-audio", ofType:"mp3") else {
            return
        }
        let fileURL = URL(fileURLWithPath: path)
        do {
            player = try AVAudioPlayer(contentsOf: fileURL)
        } catch let ex {
            print(ex.localizedDescription)
        }
        player?.prepareToPlay()
        player?.delegate = self
    }
}

回答by Badr

I had to declare a global player variable

我必须声明一个全局玩家变量

var player: AVAudioPlayer!

and set it in viewDidLoad

并将其设置在 viewDidLoad

   override func viewDidLoad() {
        super.viewDidLoad()
        player = AVAudioPlayer()
    }

Then I could play the audio file wherever like this:

然后我可以像这样在任何地方播放音频文件：

    func playAudioFile(){
    do {
        if audioFileUrl == nil{
            return 
        }
           try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)
           try AVAudioSession.sharedInstance().setActive(true)
           /* The following line is required for the player to work on iOS 11. Change the file type accordingly*/
           player = try AVAudioPlayer(contentsOf: audioFileUrl, fileTypeHint: AVFileType.m4a.rawValue)
           /* iOS 10 and earlier require the following line:
           player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileTypeMPEGLayer3) */
           guard let player = player else { return }
           player.play()
        print("PLAYING::::: \(audioFileUrl)")
       }
    catch let error {
           print(error.localizedDescription)
       }
}

}

}

回答by William Kane

var audioPlayer = AVAudioPlayer()
var alertSound = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("KiepRongBuon", ofType: "mp3")!)
        AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil)
        AVAudioSession.sharedInstance().setActive(true, error: nil)
        var error:NSError?
        audioPlayer = AVAudioPlayer(contentsOfURL: alertSound, error: &error)
        audioPlayer.prepareToPlay()
        audioPlayer.play()

回答by Prashanth Ds

I used the below code in my app and it works. Hope that is helpful.

我在我的应用程序中使用了以下代码并且它有效。希望这是有帮助的。

var audioPlayer: AVAudioPlayer!
if var filePath = NSBundle.mainBundle().pathForResource("audioFile", ofType:"mp3"){

     var filePathUrl = NSURL.fileURLWithPath(filePath)
     audioPlayer = AVAudioPlayer(contentsOfURL: filePathUrl, error: nil)
     audioPlayer.play()
}else {
     println("Path for audio file not found")
}

回答by Iyyappan Ravi

In Swift Coding using Try catch, this issues will solve and play audio for me and my code below,

在使用 Try catch 的 Swift Coding 中，此问题将为我和下面的代码解决并播放音频，

var playerVal = AVAudioPlayer()

         @IBAction func btnPlayAction(sender: AnyObject) {
                let fileURL: NSURL = NSURL(string: url)!
                    let soundData = NSData(contentsOfURL: fileURL)

                    do {
                        playerVal = try AVAudioPlayer(data: soundData!)
                    }
                    catch {
                        print("Something bad happened. Try catching specific errors to narrow things down",error)
                    }

                    playerVal.delegate = self
                    playerVal.prepareToPlay()

                    playerVal.play()

              }

回答by ronak patel

swift 3.0:

快速 3.0：

 import UIKit
    import AVFoundation

    class ViewController: UIViewController
    {
        var audioplayer = AVAudioPlayer()

        @IBAction func Play(_ sender: Any)
        {
            audioplayer.play()
        }
        @IBAction func Pause(_ sender: Any)
        {
            if audioplayer.isPlaying
            {
                audioplayer.pause()
            }
            else
            {

            }
        }
        @IBAction func Restart(_ sender: Any)
        {
            if audioplayer.isPlaying
            {
                audioplayer.currentTime = 0
                audioplayer.play()
            }
            else
            {
                audioplayer.play()
            }

        }
        override func viewDidLoad()
        {
            super.viewDidLoad()

            do
            {
                audioplayer = try AVAudioPlayer(contentsOf:URL.init(fileURLWithPath:Bundle.main.path(forResource:"bahubali", ofType: "mp3")!))
                audioplayer.prepareToPlay()

                var audioSession = AVAudioSession.sharedInstance()

                do
                {
                    try audioSession.setCategory(AVAudioSessionCategoryPlayback)
                }

                catch
                {

                }
            }
            catch
            {
                print (error)
            }

        }
     }