title: How to play files from external storage to MediaPlayer with SeekBars?
body: <p>I have a problem with my MediaPlayer. I wrote the permissions for reading the external storage but I can't play files when I click on them.
  I also have two seeksbars, one for the volume and one for song progression.
  The errors is on MediaPlayer.create(), but without this function, the app crashed.</p>
  
  <p>'$' `@Override
      protected void onCreate(Bundle savedInstanceState) { <br>
          super.onCreate(savedInstanceState); <br>
          setContentView(R.layout.activity_seekbar); <br></p>
  
  <pre><code>   // mplayer = MediaPlayer.create(this, ); &lt;br&gt;
      audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); &lt;br&gt;
      int volumeMax = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC); &lt;br&gt;
      int volumeCorrente = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC); &lt;br&gt;
  
      SeekBar controlloVolume = (SeekBar) findViewById(R.id.seekBar); &lt;br&gt;
      controlloVolume.setMax(volumeMax); &lt;br&gt;
      controlloVolume.setProgress(volumeCorrente); &lt;br&gt;` '$'
  </code></pre>