How to get StackPanel's children to fill maximum space downward?

Question

I simply want flowing text on the left, and a help box on the right.

The help box should extend all the way to the bottom.

If you take out the outer St

Answer 1

You can use SpicyTaco.AutoGrid - a modified version of StackPanel:

First button will be fill.

You can install it via NuGet:

Install-Package SpicyTaco.AutoGrid

I recommend taking a look at SpicyTaco.AutoGrid. It's very useful for forms in WPF instead of DockPanel, StackPanel and Grid and solve problem with stretching very easy and gracefully. Just look at readme on GitHub.