MediaPlayer doesn't work after onPause and onResume

I'm developing an Android 2.2 application.

I have the following Activity:

public class StartActivity extends Activity {

    private MediaPlayer mp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.startpage);
    }

    @Override
    protected void onResume() {
        super.onResume();
        I开发者_如何学PythonmageView ship = (ImageView)findViewById(R.id.greekShip);

        ship.startAnimation(AnimationUtils.loadAnimation(this, R.anim.translate_right));

        if (mp == null) {
            mp = MediaPlayer.create(getApplicationContext(), R.raw.oceanwave);
        }
        else {
            if (mp.isPlaying())
                mp.stop();
            mp.reset();
            try {
                mp.prepare();
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        mp.start();
    }

    @Override
    protected void onPause() {
        super.onPause();

        if (mp != null) {
            if (mp.isPlaying())
                mp.stop();
        }
    }
}

If I press home button on my telephone, the sound stops. But if I restart the app, the mediaplayer starts but I can't hear anything.

Do you know where is the problem?

---

mp.prepare() is only in the else code. Based on your code, I would release mp when the activity is stopped to free up the resources while not being used, then you can create a new one in onResume()