title: WPF bind point to UserControl
body: <p>I have a user control that contains <code>2 DoubleUpDown</code>, I have bound point to that controls</p>
  
  <pre><code>&lt;DoubleUpDown x:Name="X" Grid.Column="1" Grid.Row="0" Value="{Binding Path=Value.X, Mode=TwoWay" /&gt;
  &lt;DoubleUpDown x:Name="Y" Grid.Column="1" Grid.Row="1" Value="{Binding Path=Value.Y, Mode=TwoWay}" /&gt;
  </code></pre>
  
  <p>controls get updated pretty well when I change Value from outside, but Value stays unchanged when I change controls data.</p>
  
  <p>I bound Value to user control from code inside</p>
  
  <pre><code>Point2DEditorView editor = new Point2DEditorView();
  Binding binding = new Binding("Value");
  binding.Mode = BindingMode.TwoWay;
  editor.SetBinding(Point2DEditorView.ValueProperty, binding);
  </code></pre>
  
  <p>and <code>Point2DEditorView.Value</code> also changed when I insert new coordinates into controls. But that does not affect bound Value.</p>