title: Border per column header
body: <p>I want to create a table on wpf that each column header has a round corner this is what i got so far:</p>
  
  <p><a href="https://i.stack.imgur.com/1EJTa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1EJTa.png" alt="enter image description here"></a></p>
  
  <p>as you can see, i have the desired outcome with a little un desired outcome.
  the undesired out come is that the all data grid header itself (not the columns) is getting the same border, i need to make it transparent, how can i do that?</p>
  
  <p>this is the part of the style:</p>
  
  <pre><code>&lt;DataGrid.ColumnHeaderStyle&gt;
      &lt;Style TargetType="{x:Type DataGridColumnHeader}"&gt;
          &lt;Setter Property="SeparatorBrush"  Value="Transparent"/&gt;
          &lt;Setter Property="Margin" Value="2"/&gt;
          &lt;Setter Property="Template"&gt;
              &lt;Setter.Value&gt;
                  &lt;ControlTemplate&gt;                                        
                          &lt;Grid&gt;
                              &lt;Border CornerRadius="5 5 0 0" BorderThickness="1" BorderBrush="Black"&gt;
                                  &lt;TextBlock Text="{Binding }"/&gt;
                              &lt;/Border&gt;
                          &lt;/Grid&gt;                                        
                  &lt;/ControlTemplate&gt;
              &lt;/Setter.Value&gt;
          &lt;/Setter&gt;
      &lt;/Style&gt;
  &lt;/DataGrid.ColumnHeaderStyle&gt;  
  </code></pre>