How could I put a border on my grid control in WPF?

If you just want an outer border, the easiest way is to put it in a Border control:

<Border BorderBrush="Black" BorderThickness="2">
    <Grid>
       <!-- Grid contents here -->
    </Grid>
</Border>

The reason you're seeing the border completely fill your control is that, by default, it's HorizontalAlignment and VerticalAlignment are set to Stretch. Try the following:

<Grid>
    <Border  HorizontalAlignment="Left" VerticalAlignment="Top"  BorderBrush="Black" BorderThickness="2">
        <Grid Height="166" HorizontalAlignment="Left" Margin="12,12,0,0" Name="grid1" VerticalAlignment="Top" Width="479" Background="#FFF2F2F2" />
    </Border>
</Grid>

This should get you what you're after (though you may want to put a margin on all 4 sides, not just 2...)


If nesting your grid in a border control

<Border>
    <Grid>
    </Grid>
</Border>

does not do what you want, then you are going to have to make your own control template for the grid (or border) that DOES do what you want.