Question

I have a service bound to an activity. The activity is a ListView of playable files. The service plays a certain audio file, passed from the Activty. In the previous version I hadn’t had the Service bind, so when clicking multiple times on a play element, multiple instances of sounds would occur. I thought I could solve this by binding the service, so I would communicate every time with the same instance, however it still plays multiple files if they are clicked. Maybe i understood the concept of binding wrong, I’m not sure, the android documentation is sometimes a bit vague and misleading. Here is my code, thanks for any input.

Activity:

public class ViewSounds extends ListActivity {

  private PlayService myService;

  @Override
  public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setVolumeControlStream(AudioManager.STREAM_MUSIC);

  // Bind Service
  Intent intent = new Intent(ViewSounds.this, PlayService.class);       
  getApplicationContext().bindService(intent, serviceConncetion, BIND_AUTO_CREATE); 

  // Get list vars
  String[] lex_names = getResources().getStringArray(R.array.lex_names);
  //final String[] lex_files = getResources().getStringArray(R.array.lex_files);

  setListAdapter(new ArrayAdapter<String>(this, R.layout.list_sounds, lex_names));  
  final ListView lv = getListView();
  lv.setTextFilterEnabled(true);

  lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                   

    //int playFile = getResources().getIdentifier(lex_files[position], "raw", getPackageName());   
     myService.playAudio();

    }
  });   
  }  

  private ServiceConnection serviceConncetion = new ServiceConnection() { 

   @Override
   public void onServiceConnected(ComponentName name, IBinder service) { 
         // TODO Auto-generated method stub 
         myService = ((PlayService.MyBinder)service).getService();                   
         } 

         @Override
         public void onServiceDisconnected(ComponentName name) {
         // TODO Auto-generated method stub 
         myService = null; 
         } 
        }; 

         @Override
         public void onDestroy(){ 
         super.onDestroy(); 
         unbindService(serviceConncetion);    
         }
 }

Service:

public class PlayService extends Service {

MediaPlayer player;

private final IBinder binder = new MyBinder();

@Override
public IBinder onBind(Intent intent) {
    return binder;
}       

public class MyBinder extends Binder {
     PlayService getService() {
        return PlayService.this;
    }
}

@Override
public void onCreate() {
    super.onCreate();
}

public void playAudio(){   
            // I hardcoded the file name for this preview

    player = MediaPlayer.create(this, R.raw.no_harm);
    player.setLooping(false); // Set looping
    if (!player.isPlaying()) {      
    player.start(); 
    }
 }

public void onStart(Intent intent, int startId){
    super.onStart(intent, startId);
    Toast.makeText(this,"Service created ...", Toast.LENGTH_LONG).show();

    // Get veriable from Activity
    // int extras; 
    // extras = intent.getExtras().getInt("playFile");          

}
@Override
public void onDestroy() {
    super.onDestroy();
}
}

Answer 1

You should stop playback of previous file before playing another file. In your code you actually creating new MediaPlayer for each new media file.

Here is how your playAudio should look like:

public void playAudio(){   
   // I hardcoded the file name for this preview

   if(player != null){
       player.release();
   }

   player = MediaPlayer.create(this, R.raw.no_harm);
   player.setLooping(false); // Set looping
   if (!player.isPlaying()) {      
      player.start(); 
   }
}

But you should avoid creation of new media players for each new playback. You could do this next way:

public void playAudio(){   
   // I hardcoded the file name for this preview

   if(player == null){
        player = new MediaPlayer();
   }

   if(player.isPlaying()){  
        player.stop();
   }

   player.reset();
   player.setLooping(false);

   player.setOnPreparedListener(new MediaPlayer.OnPreparedListener(){
        @Override
        void onPrepared(MediaPlayer mp){
            mp.play();
        }
   });       
   player.prepareAsync(); 
}

You should also use onSetErrorListener(...) and onSetComlpletionListener(...) for more control over the player. So that your activity can react on state changes in MediaPlayer.