title: WPF DataGridCheckBoxColumn: how to hide the checkbox if the binding value is null?
body: <p>I have a datagrid with a DataGridCheckBoxColumn binding to nullable bool. I'd like to hide the checkbox completely if the value is null. I tried the following trigger, but it doesn't work:</p>
  
  <pre><code>&lt;Style TargetType="CheckBox"&gt;
      &lt;Style.Triggers&gt;
          &lt;Trigger Property="IsChecked" Value="{x:Null}"&gt;
              &lt;Setter Property="Visibility" Value="Hidden"/&gt;
          &lt;/Trigger&gt;
      &lt;/Style.Triggers&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>Is it possible at all? Your help is much appreciated!</p>