title: Trouble styling data-bound WPF ComboBoxItem
body: <p>I have a ComboBox, bound to a DataTable. I'm trying to add an extra ComboBoxItem to the top of the list, where I can put a link to customize the list. Currently I am just inserting a dummy row to the top of my DataTable, and then using a DataTrigger on the ComboBox to make it appear correctly. However, I'm not quite getting the correct result.</p>
  
  <p>I've tried two methods. In the first, my DataTrigger replaces the dummy item with a ControlTemplate, which contains a TextBlock.</p>
  
  <pre><code>&lt;ComboBox IsEditable="True" Name="comboWell" ItemsSource="{Binding}" DisplayMemberPath="wellId"&gt;
      &lt;ComboBox.ItemContainerStyle&gt;
          &lt;Style TargetType="{x:Type ComboBoxItem}"&gt;
              &lt;Style.Triggers&gt;
                  &lt;DataTrigger Binding="{Binding wellId}" Value="(settings)"&gt;
                      &lt;Setter Property="Template"&gt;
                          &lt;Setter.Value&gt;
                              &lt;ControlTemplate TargetType="ComboBoxItem"&gt;
                                  &lt;TextBlock Text="Customize..." /&gt;
                              &lt;/ControlTemplate&gt;
                          &lt;/Setter.Value&gt;
                      &lt;/Setter&gt;
                  &lt;/DataTrigger&gt;
              &lt;/Style.Triggers&gt;
          &lt;/Style&gt;
      &lt;/ComboBox.ItemContainerStyle&gt;
  &lt;/ComboBox&gt;
  </code></pre>
  
  <p>The result looks right, but there is no mouseover highlight on that item. The rest of the list works fine, but that one item doesn't react at all when I mouse over it. I've tried adding extra triggers and styles to apply a mouseover effect, but I get no change.</p>
  
  <p>The second method I tried was just to alter the appearance of the item rather than completely replace it with a ControlTemplate.</p>
  
  <pre><code>&lt;ComboBox IsEditable="True" Name="comboWell" ItemsSource="{Binding}" DisplayMemberPath="wellId"&gt;
      &lt;ComboBox.ItemContainerStyle&gt;
          &lt;Style TargetType="{x:Type ComboBoxItem}"&gt;
              &lt;Style.Triggers&gt;
                  &lt;DataTrigger Binding="{Binding wellId}" Value="(settings)"&gt;
                      &lt;Setter Property="Content" Value="Customize..." /&gt;
                  &lt;/DataTrigger&gt;
              &lt;/Style.Triggers&gt;
          &lt;/Style&gt;
      &lt;/ComboBox.ItemContainerStyle&gt;
  &lt;/ComboBox&gt;
  </code></pre>
  
  <p>This one functions like a regular list item, mouseover works fine. However, the item is blank. Neither the original text, nor the text I try to set in the DataTrigger, are there. No errors, just an empty list item.</p>
  
  <p>Is there a better way to accomplish this?</p>