title: Blank screen when restoring screenBrightness Android
body: <p>**Please note, Im just trying to turn off the display. If you have better method of doing this please suggest it :)</p>
  
  <p>I am using</p>
  
  <pre><code>params.screenBrightness = 0;
  getWindow().setAttributes(params);
  </code></pre>
  
  <p>and</p>
  
  <pre><code>params.flags |= LayoutParams.FLAG_KEEP_SCREEN_ON;
  params.screenBrightness = -1;
  getWindow().setAttributes(params);
  </code></pre>
  
  <p>to turn on/off the display. When I turn the screen back on, all I get is a blank screen with the backlight on. </p>
  
  <p>Any idea why this is happening?
  Thank you
  Mike</p>