I ran into a bug doing some layout with nested controls. Here's a simplified repro:

In WPF setting HorizontalAlignment on a control will let it resize itself if it's inside a stretched element. For example:

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="Auto" Width="Auto">
  <Grid>
    <StackPanel>
     <Button Content="asd" HorizontalAlignment="Center" />
  </StackPanel>
 </Grid>
</Window>

This will show a button not much larger than it's content, centered in the Window. However, doing the same in Silverlight fails:

<UserControl x:Class="SilverlightApplication1.Page"
    xmlns="http://schemas.microsoft.com/client/2007"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="Auto" Height="Auto">
 <Grid>
  <StackPanel>
   <Button Content="asd" HorizontalAlignment="Center" />
  </StackPanel>
 </Grid>
</UserControl>

The button is stretched across the entire window.

My WPF-layout-powers are not that strong, so it's quite possible that I'm missing something here. But it does appear as if SL isn't behaving how it should.

Thanks,
Michael

Hello, this is a known problem which is caused by Button's default template. As you've probably noticed, there's a curve in a Button.

<Path x:Name="CurvedBevel" Stretch="Fill" Margin="3,0,3,0" Data="F1 M 0,0.02 V 0.15 C 0.15,0.22 0.30,0.25 0.50,0.26 C 0.70,0.26 0.85,0.22 1,0.15 V 0.02 L 0.97,0 H 0.02 L 0,0.02 Z">

Nice as it is, this will cause layout problems. Add this Path to a WPF's Button's template, and you'll get the same result. So you have to override the Button's template, and remove this Path or so...

shanaolanxing - Please mark the posts as answers if they help and unmark if they don't.

Awesome, thanks. So we'll just restyle and everything will be fine.

-Michael

Thanks everybody, That's a known bug in Button's default template, and should be fixed in RTM.