Question

In my application background music is controlled by an asynctask. When the home button is pressed the music shuts off. When the power button is pressed it just continues playing. I also realized if i press the power button then resume it it starts to copies of the song at the same time.

private single s;
private BackgroundSound mBackgroundSound = new BackgroundSound();


protected void onPause(){
    super.onPause();
    Log.d("mSTATE","PAUSE");
    s.onPause();
    mBackgroundSound.cancel(true);
}

public void onBackPressed() {
       super.onBackPressed();
       return;
}

protected void onDestroy(){
    super.onDestroy();
    Log.d("mState","DESTROY");
}

public void onWindowFocusChanged(boolean change){
    super.onWindowFocusChanged(change);

}

@Override
protected void onResume(){
    super.onResume();
    mBackgroundSound = new BackgroundSound();
    mBackgroundSound.execute(null);
    Log.d("mSTATE","RESUME");
    s.onResume();

}

@Override
protected void onStop(){
    super.onStop();
    Log.d("mSTATE","STOP");
    s.freeMemory();
    mBackgroundSound.end();


}

@Override
protected void onRestart(){
    super.onRestart();
    Log.d("mSTATE","RESTART");
}

@Override 
protected void onStart(){
    super.onStart();
    Log.d("mSTATE","STARTER");
}


public class BackgroundSound extends AsyncTask<Void, Void, Void> {
    private MediaPlayer player;
    protected void onPreExecute() {
        player = MediaPlayer.create(SingleActivity.this, R.raw.song);
    }
    @Override
    protected Void doInBackground(Void... params) {

        player.setLooping(true);
        AudioManager mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); 
         int currentVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_RING);
         int maxRingerVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_RING);
         double proportion = currentVolume/(double)maxRingerVolume;
         int maxMusicVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
         int volume = (int)(proportion * maxMusicVolume);
        player.setVolume(volume,volume); 
        player.setLooping(true);
        player.start(); 
        return null;
    }

    public void end(){
        player.stop();
        player.release();
    }

}

Answer 1

AFAIK when Power button is pressed, only onpause is called and no onstop is called, Since no other activity has come to the foreground, Only a system window has come on top. Hence your end call is not being called.

A better way would be to override Asynctask.onCancelled and call Asynctask.cancel method in OnPause rather than onstop