如何删除我的网格角

How to remove my Grid corners

我的Grid:

<Grid HorizontalAlignment="Center" Height="65" Margin="0,0,0,0" VerticalAlignment="Center" Width="352" Background="Gray">
    <Border BorderBrush="#FF000000" BorderThickness="1,1,1,1" CornerRadius="8,8,8,8"/>
</Grid>

如何让我的角变透明?

在边框上设置背景并将边框放在网格周围

<Border BorderBrush="#FF000000" Height="65" Width="352" 
    BorderThickness="1,1,1,1" CornerRadius="8,8,8,8" Background="Gray">
    <Grid HorizontalAlignment="Center" Margin="0,0,0,0"  VerticalAlignment="Center" />
</Border>