Question

I want to fill a panel with rectangles, and when the panel is resized, the rectangles should resize as well.

Why doesn’t the following work?

<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
    <Rectangle Fill="Red" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
    <Rectangle Fill="Green" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
    <Rectangle Fill="Blue" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
  </StackPanel>
</Page>

I would prefer not to use a Grid because of the pain of adding/removing columns and rearranging the children. (I was looking forward to StackPanel because if I wanted to add a yellow Rectangle at the beginning, I just declare it. I don’t have to re-order the others by hand.)

Answer 1

Or a UniformGrid:

<UniformGrid Columns="1">
    <Rectangle Fill="Red"/>
    <Rectangle Fill="Green"/>
    <Rectangle Fill="Blue"/>
</UniformGrid>