title: Turn the screen in to totally dark when press the button on the screen
body: <p>How to code the android to turn the screen completely off just like you press the power button to lock your screen.</p>
  
  <p>I want the user to press the button on the screen and then screen goes off.</p>
  
  <p>I have tried (with permission):</p>
  
  <pre><code>PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "tag");
  </code></pre>
  
  <p>wl.acquire();</p>
  
  <p>but not working for me, please help! thank you!</p>