title: Private WPF dependency property
body: <p>In my WPF project I need to animate several properties with the same value. So my idea was to create a custom, private dependency property to which the animation will be applied. Unfortunately this doesn't seem to work. <code>DependencyPropertyDescriptor.FromProperty()</code> always returns <code>null</code> for this property. Here is the code:</p>
  
  <pre><code>public partial class PedestrianVisual : UserControl {
    private static readonly DependencyProperty CurrentInaccuracyRadiusProperty =
      DependencyProperty.Register("CurrentInaccuracyRadius", typeof(double), typeof(PedestrianVisual));
    private double CurrentInaccuracyRadius {
      get { return (double)GetValue(CurrentInaccuracyRadiusProperty); }
      set { SetValue(CurrentInaccuracyRadiusProperty, value); }
    }
  
    public PedestrianVisual() {
      InitializeComponent();
  
      // This returns "null" all the time.
      DependencyPropertyDescriptor dpd = DependencyPropertyDescriptor.FromProperty(
        CurrentInaccuracyRadiusProperty, typeof(PedestrianVisual));
      dpd.AddValueChanged(this, (s, e) =&gt; { 
        UpdateInaccuracyCircle((double)GetValue(CurrentInaccuracyRadiusProperty)); 
      });
    }
  
    private void UpdateInaccuracyCircle(double curRadius) {
      // do something here
    }
  }
  </code></pre>
  
  <p>Is there any other way to create a private dependency property?</p>