如果只需要一个外部边框，最简单的方法是将其放在Border控件中:

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>

看到边框完全填充控件的原因是，默认情况下，将Horizo​​ntalAlignment和VerticalAlignment设置为Stretch.请尝试以下操作:

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>

这应该可以让您得到满意的结果(尽管您可能希望在所有4个方面都留出边距，而不仅仅是2个...)

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