How to anchor controls in WPF?

Question

I have a a TreeView that fills the top part of the application, but since the number of items in the TreeView changes, my Apply button changes its

Answer 1

To achieve anchoring, Set following properties:

• Width="auto"
• Height="auto"
• VerticalAlignment="Stretch"
• HorizontalAlignment="Stretch"
• Set margins as needed.

Example: