Android 播放资产目录中的音频文件

Play audio file from the assets directory

提问by Catalin Morosan

I have the following code:

我有以下代码：

AssetFileDescriptor afd = getAssets().openFd("AudioFile.mp3");
player = new MediaPlayer();
player.setDataSource(afd.getFileDescriptor());
player.prepare();
player.start();

The problem is that, when I run this code, it starts playing all the audio files in the assets directory, in alphabetical order instead of just playing the audio file I requested. What am I doing wrong? Is there a better way to play audio files from the assets directory?

问题是，当我运行此代码时，它开始按字母顺序播放资产目录中的所有音频文件，而不仅仅是播放我请求的音频文件。我究竟做错了什么？有没有更好的方法来播放资产目录中的音频文件？

Follow-up question: Is there a difference between keeping audio files in the assets directory and keeping them in the res/raw directory? Besides the fact that they don't get ids if they are in the assets directory. If I move the audio files to the res/raw folder then I have a problem with reusing MediaPlayers because there is no id parameter for setDataSource(). I can't find a good guideline for handling this kind of problem.

后续问题：将音频文件保存在assets目录下和保存在res/raw目录下有区别吗？此外，如果他们在资产目录中，他们就不会获得 id。如果我将音频文件移动到 res/raw 文件夹，那么我在重用MediaPlayers 时会遇到问题，因为.s没有 id 参数setDataSource()。我找不到处理此类问题的好指南。

回答by Sarwar Erfan

player.setDataSource(afd.getFileDescriptor(),afd.getStartOffset(),afd.getLength());

Your version would work if you had only one file in the assets directory. The asset directory contents are not actually 'real files' on disk. All of them are put together one after another. So, if you do not specify where to start and how many bytes to read, the player will read up to the end (that is, will keep playing all the files in assets directory)

如果您的资产目录中只有一个文件，您的版本就可以工作。资产目录内容实际上并不是磁盘上的“真实文件”。所有这些都一个接一个地放在一起。因此，如果您不指定从哪里开始以及读取多少字节，播放器将读取到最后（即，将继续播放资产目录中的所有文件）

回答by Siddhpura Amit

This function will work properly :)

此功能将正常工作:)

// MediaPlayer m; /*assume, somewhere in the global scope...*/

public void playBeep() {
    try {
        if (m.isPlaying()) {
            m.stop();
            m.release();
            m = new MediaPlayer();
        }

        AssetFileDescriptor descriptor = getAssets().openFd("beepbeep.mp3");
        m.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
        descriptor.close();

        m.prepare();
        m.setVolume(1f, 1f);
        m.setLooping(true);
        m.start();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

回答by Alecs

Here my static version:

这是我的静态版本：

public static void playAssetSound(Context context, String soundFileName) {
    try {
        MediaPlayer mediaPlayer = new MediaPlayer();

        AssetFileDescriptor descriptor = context.getAssets().openFd(soundFileName);
        mediaPlayer.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
        descriptor.close();

        mediaPlayer.prepare();
        mediaPlayer.setVolume(1f, 1f);
        mediaPlayer.setLooping(false);
        mediaPlayer.start();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

回答by Hadid Graphics

Fix of above function for play and pause

修复上述播放和暂停功能

  public void playBeep ( String word )
{
    try
    {
        if ( ( m == null ) )
        {

            m = new MediaPlayer ();
        }
        else if( m != null&&lastPlayed.equalsIgnoreCase (word)){
            m.stop();
            m.release ();
            m=null;
            lastPlayed="";
            return;
        }else if(m != null){
            m.release ();
            m = new MediaPlayer ();
        }
        lastPlayed=word;

        AssetFileDescriptor descriptor = context.getAssets ().openFd ( "rings/" + word + ".mp3" );
        long                start      = descriptor.getStartOffset ();
        long                end        = descriptor.getLength ();

        // get title
        // songTitle=songsList.get(songIndex).get("songTitle");
        // set the data source
        try
        {
            m.setDataSource ( descriptor.getFileDescriptor (), start, end );
        }
        catch ( Exception e )
        {
            Log.e ( "MUSIC SERVICE", "Error setting data source", e );
        }

        m.prepare ();
        m.setVolume ( 1f, 1f );
        // m.setLooping(true);
        m.start ();
    }
    catch ( Exception e )
    {
        e.printStackTrace ();
    }
}

回答by MODERN

start sound

开始声音

startSound("mp3/ba.mp3");

method

方法

private void startSound(String filename) {
    AssetFileDescriptor afd = null;
    try {
        afd = getResources().getAssets().openFd(filename);
    } catch (IOException e) {
        e.printStackTrace();
    }
    MediaPlayer player = new MediaPlayer();
    try {
        assert afd != null;
        player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        player.prepare();
    } catch (IOException e) {
        e.printStackTrace();
    }
    player.start();
}

回答by Altivo

this works for me:

这对我有用：

public static class eSound_Def
{
  private static Android.Media.MediaPlayer mpBeep;

  public static void InitSounds( Android.Content.Res.AssetManager Assets )
  {
    mpBeep = new Android.Media.MediaPlayer();

    InitSound_Beep( Assets );
  }

  private static void InitSound_Beep( Android.Content.Res.AssetManager Assets )
  {
    Android.Content.Res.AssetFileDescriptor AFD;

    AFD = Assets.OpenFd( "Sounds/beep-06.mp3" );
    mpBeep.SetDataSource( AFD.FileDescriptor, AFD.StartOffset, AFD.Length );
    AFD.Close();

    mpBeep.Prepare();
    mpBeep.SetVolume( 1f, 1f );
    mpBeep.Looping = false;
  }

  public static void PlaySound_Beep()
  {
    if (mpBeep.IsPlaying == true) 
    {
      mpBeep.Stop();
      mpBeep.Reset();
      InitSound_Beep(); 
    }
    mpBeep.Start();
  }
}

In main activity, on create:

在主要活动中，创建：

protected override void OnCreate( Bundle savedInstanceState )
{
  base.OnCreate( savedInstanceState );
  SetContentView( Resource.Layout.lmain_activity );
  ...
  eSound_Def.InitSounds( Assets );
  ...
}

how to use in code (on button click):

如何在代码中使用（点击按钮）：

private void bButton_Click( object sender, EventArgs e )
{
  eSound_Def.PlaySound_Beep();
}