title: silverlight column header disappers on applying header style template
body: <p>I have a  Silverlight <code>DataGrid</code> with two columns. The headers of these two columns header  have to be shown with a text box and column header title or name so that the text box can be used for filtering later.</p>
  
  <p>So, I have used the following code to display the text box using a style:</p>
  
  <pre><code>&lt;Style x:Name="mytemplate"
         x:Key="mytemplate"
         xmlns:dataprimitives="clr-namespace:System.Windows.Controls.Primitives;assembly=System.Windows.Controls.Data"
         TargetType="dataprimitives:DataGridColumnHeader"&gt;
     &lt;Setter Property="ContentTemplate" &gt;
         &lt;Setter.Value&gt;
             &lt;DataTemplate x:Name="ColHeaderTemplategrid"&gt;                      
                 &lt;StackPanel&gt;                             
                     &lt;TextBox x:Name="txtfilterBox"  KeyDown="txtfilterBox_KeyDown" Width="40"/&gt;
                 &lt;/StackPanel&gt;
             &lt;/DataTemplate&gt;
         &lt;/Setter.Value&gt;
     &lt;/Setter&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>and I have applied the style to the column headers as below:</p>
  
  <pre><code> ((DataGridTextColumn)column[0]).HeaderStyle = mytemplate;
   ((DataGridTextColumn)column[1]).HeaderStyle = mytemplate;
  </code></pre>
  
  <p>The thing is, now the text box is visible but the column header title or name disappears?</p>
  
  <p>How do I show my column header along with the text box?</p>