Q:

rounded border on textblock issue

I am trying to give my textblocks rounded borders.  From what I've researched, I should embed a textblock within a border tag and then set the corner radius of the border.  For me, it's having the effect of putting a border around the entire row.  What am I doing wrong?  I set the color of the border to blue to show what is happening. Ideally, I would change it to the same color as the background of the textblock to just give it seamless rounded corners.
<Grid>                
   <Grid.RowDefinitions>
       <RowDefinition Height="Auto"></RowDefinition>                   
   </Grid.RowDefinitions>

   <Border Grid.Row="0" Margin="25" Grid.Column="1" Background="Blue"
           BorderThickness="1" BorderBrush="Red"  CornerRadius="30">
           <TextBlock  Margin="50" Padding="200,0,200,0"
                       FontSize="100"
                       FontWeight="Bold"
                       Background="Black"
                       Foreground="White"    
                       VerticalAlignment="Center"
                       Text="bla bla bla"
                       HorizontalAlignment="Center">
           </TextBlock>
    </Border>
</Grid>

A:

Look at the HorizontalAlignment / VerticalAlignment values for both the Grid and the Border. Set whatever is most appropriate for your requirements.
A tool such as Kaxaml is great for playing around with this sort of thing without having to build an entire application.

