WPF为window加阴影效果

<Style x:Key="for_noresize_window" TargetType="{x:Type Window}">    
     <Setter Property="AllowsTransparency" Value="true"/>        
     <Setter Property="Background" Value="Transparent"/>           
     <Setter Property="FontFamily" Value="Consolas, Microsoft YaHei"/> 
     <Setter Property="FontSize" Value="24"/>             
     <Setter Property="ResizeMode" Value="NoResize"/>         
     <Setter Property="WindowStyle" Value="None"/>    
         <Setter Property="Template">        
             <Setter.Value>             
                <ControlTemplate TargetType="{x:Type Window}">  
                    <Grid Margin="10">            
                      <Rectangle Fill="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"   
                       RadiusX="5" RadiusY="5">                       
                      <Rectangle.Effect>                                  
                           <DropShadowEffect BlurRadius="10" ShadowDepth="0"/>                  
                      </Rectangle.Effect>                  
                      </Rectangle>                      
                      <Border Background="{TemplateBinding Background}"        
                      BorderBrush="{TemplateBinding BorderBrush}"       
                      BorderThickness="{TemplateBinding BorderThickness}"  
                      Padding="{TemplateBinding Margin}"                  
                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"            
                      CornerRadius="5">                  
                           <ContentPresenter />                  
                      </Border>                      
                   </Grid>                   
                 </ControlTemplate>           
      </Setter.Value>          
    </Setter>     
</Style>