title: Can you bind a DataTrigger to an Attached Property?
body: <p>In WPF, is it possible for a DataTrigger to bind to an attached property?</p>
  
  <p>I essentially want to use a converter on an attached property to provide a style when a particular validation rule has been broken. I am using markup like the following:</p>
  
  <pre><code>&lt;DataTrigger Binding="{Binding Path=Validation.Errors, 
                         RelativeSource={RelativeSource Self}, 
                         Converter={StaticResource RequiredToBoolConverter}}" 
                         Value="True"&gt;
    &lt;Setter Property="Background" Value="LightGreen" /&gt;
  &lt;/DataTrigger&gt;
  </code></pre>
  
  <p>However, when this runs, I get the following:</p>
  
  <blockquote>
    <p>System.Windows.Data Error: 39 :
    BindingExpression path error:
    'Validation' property not found on
    'object' ''TextBox' (Name='')'.
    BindingExpression:Path=Validation.Errors;
    DataItem='TextBox' (Name=''); target
    element is 'TextBox' (Name=''); target
    property is 'NoTarget' (type 'Object')</p>
  </blockquote>
  
  <p>If I change my DataTrigger binding path to "Text", I do not get the databinding error (but of course it does not provide the behaviour I am seeking).</p>