如何在Android中实现音频连续播放，即使屏幕方向改变？

我是 Android 初学者，我需要创建 MediaPlayer 来播放音乐。当我启动我的活动时，歌曲开始播放。但当我在模拟器屏幕上更改方向时，MediaPlayer 将被重新初始化并播放另一个音频。如何避免这种情况发生？

这是我的代码：

public class Audio_Activity extends Activity {


MediaPlayer mp = null;


    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        if(isLaunched)
        {
            setContentView(R.layout.audio);
        }

        SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
        length = settings.getInt("TheOffset", 0);
        init();
        prefs = PreferenceManager.getDefaultSharedPreferences(this);
        mp = MediaPlayer.create(getApplicationContext(), R.raw.subhanallah);
        playMusic();


        mp.setOnCompletionListener(new OnCompletionListener() 
        {

            @Override
            public void onCompletion(MediaPlayer arg0) 
            {
                // TODO Auto-generated method stub

            }
        });


    }

    private void playMusic() 
    {
        httpGetAsynchTask httpGetAsyncTask = new httpGetAsynchTask();
        httpGetAsyncTask.execute();
    }



    class httpGetAsynchTask extends AsyncTask<String,Integer, Void>
    {

        protected void onPreExdcute()
        {

        }

        @Override
        protected Void doInBackground(String... arg0)
        {
            // TODO Auto-generated method stub

            final SharedPreferences.Editor prefsEdit = prefs.edit();

            Log.e("Song is playing", "in  Mediya Player ");

            mp.setLooping(false);
            mp.start();
            int millisecond=mp.getDuration();
            Log.e("Song is playing", "in  Mediya Player " + millisecond);

            prefsEdit.putBoolean("mediaplaying", true);
            prefsEdit.commit();
            //btnChapter.setEnabled(false);

            return null;

        }

        protected void onPostExecute(Void result)
        {
            super.onPostExecute(result);
            btnChapter.setEnabled(false);
        }

    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        Configuration config=getResources().getConfiguration();
        if(config.orientation == Configuration.ORIENTATION_PORTRAIT)
        {
            setContentView(R.layout.audio);
        }
        else if(config.orientation == Configuration.ORIENTATION_LANDSCAPE)
        {
            setContentView(R.layout.audio);
        }
    }

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


        SharedPreferences.Editor prefsEdit = prefs.edit();
        boolean isPlaying = prefs.getBoolean("mediaplaying", false);
        if (isPlaying)
        {
            mp.pause();
            int position = mp.getCurrentPosition();
            Log.e("Current ", "Position -> " + position);
            prefsEdit.putInt("mediaPosition", position);
            prefsEdit.commit();
        }
    }

    @Override
    protected void onResume() {

        super.onResume();

        mp.start();

        boolean isPlaying = prefs.getBoolean("mediaplaying", false);
        if (isPlaying) {
            int position = prefs.getInt("mediaPosition", 0);
            mp.seekTo(position);
            // mp.start();


        }
    } 

}

我已经对Manifest.xml文件进行了一些更改。

< android:configChanges="orientation|screenSize|keyboard" >

并创建 layout-land 文件夹。

为什么音乐会播放两次？