title: Check progress of download operation which started in background task
body: <p>I have an application where users can download some files and these files can be also downloaded via BackgroundTask triggered by push notification for example.</p>
  
  <p>When the app is not running and I receive push notification, BackgroundTask starts to download the file. If I launch the app and the file is still downloading I would like to see progress of it.</p>
  
  <p>I am able to get all downloading files <code>BackgroundDownloader.GetCurrentDownloadsAsync()</code>.</p>
  
  <p>If I have list of <code>DownloadOperation</code>, am I able to somehow check current progress of each operation? I mean if I can attach some <code>IProgress&lt;T&gt;</code> method to already running download operations.</p>
  
  <p>Or is there any other approach how to check progress of <code>DownloadOperation</code> which started in BackgroundTask?</p>
  
  <hr>
  
  <p><strong>UPDATE</strong></p>
  
  <p>If I need to see progress of downloading file I can use this approach:</p>
  
  <pre><code>await downloadOperation.StartAsync().AsTask(token, new Progress&lt;DownloadOperation&gt;(...));
  </code></pre>
  
  <p>However, if I have just instance of <code>DownloadOperation</code> which is already downloading a file, How can I check progress of the operation and inform view about any progress? There is <code>Progress</code> property which has current progress, but there is not any "progress changed event" or something like that.</p>