I am having hard times figuring this out. Here is what I need:

<StackPanel x:Name="container" VerticalAlignment="Stretch">
     <RichTextBox Height="???" />
</StackPanel>

Basically what I know I can do is to bind RichTextBox Height to it's parent's height ( Height="{Binding ElementName=container, Path=ActualHeight}". Unfortunately this only works on load, because as it seems ActualHeight and ActualWidth don't notify for changes.

So what is the best way in Silverlight 4 to tell RichTextBox or TextBlock, it doesn't matter, to fill it's parent height, and maintain scrollbar if it's content height is bigger. Is the only way to bind some Resize events and maintain the height explicitly? That seems really ugly to me?