title: UWP new MediaPlayerElement questions
body: <p>Actually i am updating my App to Windows 10 version 1607, for using all the new APIs. Before i used a MediaElement for playing audio and video. Now i moved to the new MediaPlayer and MediaPlayerElement. Now i have two questions about them:</p>
  
  <ol>
  <li><p>Is it no more possible to stop playing media? The "old" MediaElement had a method "Stop()", but this is missing on the MediaPlayerElement and also on the MediaPlayer instance itself.</p></li>
  <li><p>When i play a video and then change the source of the MediaPlayer to an audio file, i see the video for about 1-2s, until the audio file starts playing. Is it possible to clear the showing video? Set the source to null does not work.</p></li>
  </ol>
  
  <p>Best Regards</p>