title: android.intent.action.SCREEN_OFF
body: <p>I am trying to detect Screen backlight On / Off.</p>
  
  <p>I've found <code>android.intent.action.SCREEN_OFF</code> related its event. </p>
  
  <p>But I don't know how to use this. </p>
  
  <p>Can you suggest me about how to detect screen backlight on / off ? </p>
  
  <p>I missing some example or sample code. </p>
  
  <p>Thanks in advance.</p>