title: ValidationRules without binding
body: <p>I want to use the ValidationRules (and it's UI effects) on the textbox without actually binding anything to the textbox.    </p>
  
  <p>I want to  use the textbox for some input that doesn't bound to anything but need to validate the input after focus is lost using the ValidationRules.  </p>
  
  <p>Can it be done?</p>
  
  <pre><code>&lt;TextBox.Text&gt;
     &lt;Binding Path="" UpdateSourceTrigger="LostFocus"&gt;
       &lt;Binding.ValidationRules&gt;
          &lt;local:IntegersOnlyValidator/&gt;
       &lt;/Binding.ValidationRules&gt;
     &lt;/Binding&gt;
   &lt;/TextBox.Text&gt;
  </code></pre>