title: How to programmatically change background theme of Win 8.1 or Win 10 UWP app?
body: <p>I have an app for Windows Phone 8.1 and a UWP version of it. I'd like to change the background of the apps dynamically when it is changed in Windows.</p>
  
  <p>Use case would be:</p>
  
  <ol>
  <li>Start the app, the background theme is dark.</li>
  <li>Press the home button on the phone</li>
  <li>Change the background theme to light</li>
  <li>Go back to the app (basically switch to it from the background)</li>
  <li>The theme of the app would change automatically to the new theme</li>
  </ol>
  
  <p>I'd like it to be done like this, without a restart. I've seen this in other apps, so it has to be possible somehow, but I can't figure out.</p>
  
  <p>If a restart is required, that is fine too as solution B.</p>
  
  <p>Thanks.</p>