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

You can either set the HorizontalAlignment and VerticalAlignment on the TreeView or Button (I cannot tell which control you are trying to anchor), or you could place the control inside a DockPanel.

To space the control away from others use the Margin.

Margin="0 0 10 10"

will give you the margin only on the right and bottom

I hope this makes it a bit clearer: