<ScrollViewer MaxHeight="400" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Hidden" BorderBrush="Transparent">
<ScrollViewer.Effect>
<DropShadowEffect ShadowDepth="0" Color="Black" Opacity="0.5" Direction="90" BlurRadius="15"/>
</ScrollViewer.Effect>
<StackPanel x:Name="rootStp"/>
</ScrollViewer>

注：当ShadowDepth的值为0时，控件四周都会有阴影效果。