title: DependencyProperty ValidateValueCallback question
body: <p>I added a ValidateValueCallback to a DependencyProperty called A. Now in the validate callback, A shall be compared to the value of a DependencyProperty called B. But how to access the value of B in the <em>static</em> ValidateValueCallback method validateValue(object value)? Thanks for any hint!</p>
  
  <p>Sample code:</p>
  
  <pre><code>class ValidateTest : DependencyObject
  {
      public static DependencyProperty AProperty = DependencyProperty.Register("A", typeof(double), typeof(ValidateTest), new PropertyMetadata(), validateValue);
      public static DependencyProperty BProperty = DependencyProperty.Register("B", typeof(double), typeof(ValidateTest));
  
  
      static bool validateValue(object value)
      {
          // Given value shall be greater than 0 and smaller than B - but how to access the value of B?
  
          return (double)value &gt; 0 &amp;&amp; value &lt;= /* how to access the value of B ? */
      }
  }
  </code></pre>