title: WPF : Keeping default style when inheriting from ListBoxItem
body: <p>Hey Guys (and girls if any :)</p>
  
  <p>I needed a different list box selection policy than the one provided by default with WPF listboxes, i.e. beeing able to have an extended selection withou any modifier key.</p>
  
  <p>No problem on that, here is what I did : </p>
  
  <pre><code>class EnhancedCcyPairListBox : ListBox
  {
  
      protected override DependencyObject GetContainerForItemOverride()
      {
          return new CcyPairListBoxItem();
      }
  
  }
  
  internal class CcyPairListBoxItem : ListBoxItem
  {
      protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
      {
          IsSelected = !IsSelected;
  
          e.Handled = true;
      }
  }
  </code></pre>
  
  <p>I can't tell if it's the best way to do, but it seems to work exactly as I expected.</p>
  
  <p>Except that... by doing so, I have lost the defaults ListBoxItem style I had before. How can I tell to my derived classes to keep their default style ?</p>
  
  <p>Thank you very much !</p>