title: Data-bound WPF ComboBox not displaying selected value
body: <p>I have a ComboBox, bound to a DataTable. The ComboBox displays a list of values, pulled from the "wellId" column of the DataTable. The ComboBox is also styled so that I can insert a custom item into the list simply by adding a dummy row to the DataTable with the wellId field set to "(settings)".</p>
  
  <pre><code>&lt;ComboBox IsEditable="True" Name="comboWell" ItemsSource="{Binding}"&gt;
      &lt;ComboBox.ItemContainerStyle&gt;
          &lt;Style TargetType="{x:Type ComboBoxItem}"&gt;
              &lt;Setter Property="Content" Value="{Binding wellId}" /&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>For the most part, this works great. It shows the list, and all items (including the dummy items) are selectable in the drop-down list.</p>
  
  <p>However, after selecting an item from the list, whether it is a real item or a dummy item, the ComboBox doesn't show the selected item properly. Rather than showing the same value displayed in the drop-down list (the "wellId" column from the DataTable), it instead just displays the string "<strong>System.Data.DataRowView</strong>". No matter what I select, it always displays the same thing.</p>
  
  <p>If I specifically set the DisplayMemberPath on the ComboBox to "wellId", then it displays the selected item properly. However, this messes up all of the other styling I have applied, resulting in the drop-down list being filled with blank entries.</p>
  
  <p>How do I get the ComboBox to display the selected item properly?</p>