title: WPF Trigger not null
body: <p>How to trigger an action in WPF when the Property <strong>is not null</strong>? 
  This is a working solution when <strong>is null</strong>:</p>
  
  <pre><code>&lt;Style.Triggers&gt;
      &lt;DataTrigger Binding="{Binding}" Value="{x:Null}"&gt;
  
        &lt;Setter Property="Background" Value="Yellow" /&gt;
  
      &lt;/DataTrigger&gt;
  &lt;/Style.Triggers&gt;
  </code></pre>
  
  <p>I know that you cant "turn around" the condition and do what you need, but want to know</p>