title: NavigationView change selected item using back button
body: <p>I'm using a navigationview control in a UWP app, the thing is when I click the back button the focused element doesn't change to the item displayed in the contentframe. For example the clicked elements were camara, store, musica, then back button twice to display camara in the contentframe element, but musica still has the focus (blue rectangle)</p>
  
  <pre><code>private void FrameNavigated( object sender, NavigationEventArgs e )
      {
          var currentView = SystemNavigationManager.GetForCurrentView();
          if ( ContentFrame.CanGoBack )
          {
              currentView.AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
          }
          else
          {
              currentView.AppViewBackButtonVisibility = AppViewBackButtonVisibility.Collapsed;
          }
      }
  
  private void OnBackRequested( object sender, BackRequestedEventArgs e )
      {
          if ( ContentFrame.CanGoBack )
          {
              e.Handled = true;
  
              PageStackEntry pageStackEntry = ContentFrame.BackStack.LastOrDefault();
  
              ContentFrame.GoBack();
  
              if ( pageStackEntry != null )
              {
                  string nombre = pageStackEntry.SourcePageType.Name;
                  MenuItem item = subItemsMenu.FirstOrDefault(nom =&gt; nom.NombrePantalla.Equals(nombre));
  
                  navView.SelectedItem = item;
                  navView.Header = item.Encabezado;
              }
          }
      }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Ct0lC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ct0lC.png" alt="enter image description here"></a></p>