仅使用一个媒体播放器实例在 android 中播放多个音频文件

Question

我有一个类可以播放位于某些文件夹中的音频文件...问题是我无法仅使用媒体播放器的一个实例来播放多个音频文件。每次我尝试播放不同的歌曲时，都会创建一个新的 Media Class 实例，并且新歌曲与前一首歌曲并行播放，这真的很烦人......谁能帮我只使用一个 Media Payer 实例来像在普通音频播放器中一样一首一首地播放不同的歌曲

//The files are listed as an array into a ListView, so i added a ListView.OnItemClickListener to play that location which the user has selected
ListView audiolist=(ListView)findViewById(R.id.audiolist);
 audiolist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                if(position==id){

                    File mypath=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
                    String mystring=(String)audiolist.getItemAtPosition(position);
                    if(mystring.contains(".mp3")) {
                        File myfile = new File(mypath.toString(), "/" + mystring);
                        Uri newuri = Uri.fromFile(myfile);
    //I think this line is the one creating the mutiple instances of the MediaPayer
                    mp=new MediaPlayer();
                             mp.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
                       mp.setAudioAttributes(
                               new AudioAttributes.Builder().setContentType(AudioAttributes.CONTENT_TYPE_MUSIC).setUsage(AudioAttributes.USAGE_MEDIA)
                                .build()
                       );
                              try {
                                    mp.setDataSource(getApplicationContext(),newuri);
                                    mp.setDisplay(holder);
                                    mp.prepare();
                                    mp.setOnBufferingUpdateListener(Audio_Player.this);
                                    mycontroller=new MediaController(Audio_Player.this);
                                    mycontroller.setMediaPlayer(Audio_Player.this);
                                    mp.start();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                      }//end of if
                       });//end of listview method

Answer 1

根本原因

每次用户点击ListView 中的一项时，您总是会创建一个新的MediaPlayer 实例，并且不会停止当前实例。这就解释了为什么您会看到同时播放多个音频。

解决方案

如果不存在，只需创建一个新的MediaPlayer 实例，否则，在播放新实例之前停止当前实例。从

更改您的代码

File mypath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
String mystring = (String)audiolist.getItemAtPosition(position);
if (mystring.contains(".mp3")) {
    File myfile = new File(mypath.toString(), "/" + mystring);
    Uri newuri = Uri.fromFile(myfile);
    // I think this line is the one creating the mutiple instances of the MediaPayer
    mp = new MediaPlayer();
    mp.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
    mp.setAudioAttributes(
           new AudioAttributes.Builder().setContentType(AudioAttributes.CONTENT_TYPE_MUSIC).setUsage(AudioAttributes.USAGE_MEDIA)
            .build()
    );
    try {
          mp.setDataSource(getApplicationContext(),newuri);
          mp.setDisplay(holder);
          mp.prepare();
          mp.setOnBufferingUpdateListener(Audio_Player.this);
          mycontroller=new MediaController(Audio_Player.this);
          mycontroller.setMediaPlayer(Audio_Player.this);
          mp.start();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

到

File mypath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
String mystring = (String) audiolist.getItemAtPosition(position);
if (mystring.contains(".mp3")) {
    File myfile = new File(mypath.toString(), "/" + mystring);
    Uri newuri = Uri.fromFile(myfile);
    // I think this line is the one creating the mutiple instances of the MediaPayer

    // Create a new MediaPlayer instance if there is no one existing.
    if (mp == null) {
        mp = new MediaPlayer();
        mp.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
        AudioAttributes.Builder builder = new AudioAttributes.Builder()
                .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
                .setUsage(AudioAttributes.USAGE_MEDIA);
        mp.setAudioAttributes(builder.build());
        mp.setOnBufferingUpdateListener(Audio_Player.this);
        mycontroller = new MediaController(Audio_Player.this);
        mycontroller.setMediaPlayer(Audio_Player.this);
        mp.setDisplay(holder);
    }

    // If the MediaPlayer is playing, then stop it and switch to another audio,
    try {
        if (mp.isPlaying()) {
            mp.reset();
        }
        mp.setDataSource(getApplicationContext(), newuri);
        mp.prepare();
        mp.start();
    } catch (IOException e) {
        e.printStackTrace();
    }
}//end of if