title: Destroy Datacontext on leaving page
body: <p>I set <code>DataContext</code> in <code>Page.xaml.cs</code></p>
  
  <pre><code>DataContext = new PageViewModel();
  </code></pre>
  
  <p>In <code>PageViewModel</code> I create Data Manager, which subscribes to different event, load data, generate event for ViewModel.</p>
  
  <p>But, when I leave page my ViewModel and DataManager objects continue to live and when I go to this page again, new ViewModel and DataManager created, now there are two object load same data etc.
  How to avoid this leak?</p>