title: Hide Textblock if <Run> is empty WPF
body: <p>I have a <code>TextBlock</code> that i want to hide if property <code>Commission.Vehicle.Owner.Name</code> is empty. The code look like this. Of course this doesn't work, the <code>TextBlock</code> property Text will always be empty..</p>
  
  <pre><code>&lt;Style x:Key="CollapsableTextBlock" TargetType="TextBlock"&gt;
      &lt;Style.Triggers&gt;
          &lt;Trigger Property="Text" Value=""&gt;
             &lt;Setter Property="Visibility" Value="Collapsed"/&gt;
          &lt;/Trigger&gt;
      &lt;/Style.Triggers&gt;
  &lt;/Style&gt;
  
  &lt;TextBlock Style="{DynamicResource CollapsableTextBlock}"&gt;
      &lt;Run Text="Owner: "/&gt;
      &lt;Run Text="{Binding Commission.Vehicle.Owner.Name}"/&gt;
  &lt;/TextBlock&gt;
  </code></pre>
  
  <p>Anyone with an idea? Thanks!</p>