Dropshadow UserControl - wpf

Question

I think doing the following is probably pretty common:
<Grid>
<Border>
<Border.Effect>
<DropShadowEffect/>
</Border.Effect>
</Border>
<SomeControl/>
</Grid>
Ok, I did that without the aid of the ide which I am admittedly lost without so forgive me if I forgot something but I think you get the point.
My question is, would it be possible to create a UserControl that would allow me to do this instead:
<DropShadowBorder>
<SomeControl/>
</DropShadowBorder>
If so, please do tell how.
EDIT: Just in case it's not immediately obvious, the point here is that I would usually put a border around my control but when I want to use a drop shadow I can't because I only want the border to have a drop shadow and not everything in it. So instead I have to create the border separately in the same grid space, but this is annoying because when I adjust margins and such on my control I have to go duplicate those changes on the border each time.

Answer 1

You can't do a user control (user control cannot have a content). You will have to create a custom control. I suggest you to create a custom control that derives from ContentControl.
The code of the custom control (default code !):
public class DropShadowBorder : ContentControl
{
static DropShadowBorder()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DropShadowBorder), new FrameworkPropertyMetadata(typeof(DropShadowBorder)));
}
}
Then define a default style for your control (in generic.xaml)
<Style TargetType="{x:Type local:DropShadowBorder}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:DropShadowBorder}">
<Grid>
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<Border.Effect>
<DropShadowEffect />
</Border.Effect>
</Border>
<ContentPresenter Content="{TemplateBinding Content}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>