title: How to prevent WPF trigger from resetting original value upon exit
body: <p>I have a mouseover-selecting listview by using trigger:</p>
  
  <pre><code>&lt;ListView.ItemContainerStyle&gt;
      &lt;Style TargetType="{x:Type ListViewItem}"&gt;
          &lt;Style.Triggers&gt;
              &lt;Trigger Property="IsMouseOver" Value="True"&gt;
                  &lt;Setter Property="IsSelected" Value="True" /&gt;
              &lt;/Trigger&gt;
          &lt;/Style.Triggers&gt;
      &lt;/Style&gt;
  &lt;/ListView.ItemContainerStyle&gt;
  </code></pre>
  
  <p>However when mouse is moved out, the trigger sets <code>IsSelected</code> back to false, which is not desired here. Is there a way to make a trigger only set-upon-enter but not reset-upon-exit?</p>