title: XAML: Refer to StaticResource in plain XAML? (without markup extension)
body: <p>I am setting a validation rule on a series of textboxes. I'd rather not create a new instance of my custom validation rule for each TextBox...</p>
  
  <pre><code>&lt;Window.Resources&gt;
    &lt;my:IsIntegerRule x:Key="IsIntegerRule"/&gt;
  &lt;/Window.Resources&gt;
  
  ...
  ...
  
  &lt;TextBox&gt;
      &lt;TextBox.Text&gt;
        &lt;Binding XPath="@num" UpdateSourceTrigger="PropertyChanged" Mode="TwoWay"&gt;
           &lt;Binding.ValidationRules&gt;
  
              &lt;-- WHAT IS THE EQUIVALENT OF WRITING: {StaticResource IsIntegerRule} here --&gt;
  
           &lt;/Binding.ValidationRules&gt;
        &lt;/Binding&gt;
       &lt;/TextBox.Text&gt;
   &lt;/TextBox&gt;
  </code></pre>
  
  <p>Can anyone help?</p>