title: Listbox.ItemContainerStyle selected item
body: <p>I have a list box with an <code>ItemContainerStyle</code> which describes the style of each element in the listbox. Like looks something like this:</p>
  
  <pre><code>&lt;ListBox.ItemContainerStyle&gt;
      &lt;Style TargetType="ListBoxItem" BasedOn="{StaticResource MyStyle}"&gt;
          &lt;Setter Property="Template"&gt;
              &lt;Setter.Value&gt;
                  &lt;ControlTemplate&gt;
                      &lt;Border BorderThickness="0,0,0,1" BorderBrush="#1f000000"  Padding="16 8"&gt;
                          &lt;Button Command={Binding MyCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=lists:MyControl}}}" /&gt;
                      &lt;/Border&gt;
                  &lt;/ControlTemplate&gt;
              &lt;/Setter.Value&gt;
          &lt;/Setter&gt;
      &lt;/Style&gt;
  &lt;/ListBox.ItemContainerStyle&gt;
  </code></pre>
  
  <p>The thing is that, when I click this button I want to know the <code>SelectedItem</code> in the listbox, which is bound in my ViewModel. This selection doesnt trigger unless I select the item first. </p>
  
  <p>Any Ideas?</p>