Hi, I am trying to create a transparent form with solid InkOverlay in C#
using Visual Studio.

I placed an inkoverlay on top of the form so I can write stuff on it.
However, now I want to make the form transparent, but I also want the
controls and the ink drawn on the inkoverlay to be solid. Is there a way to
do this? I've tried to use opacity, but that just makes everything
transparent. I've tried a few other things such as attaching the overlay to
a panel, setting the transparencyKey, etc, but nothing works. Any help would
be appreciated =).

Thanks!

WPF is the only framework that we ship, that makes this scenario "easy".

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
WindowStyle="None"
AllowsTransparency="True"
Background="#789A">
<InkCanvas Background="Transparent" Opacity="1.0">
<InkCanvas.DefaultDrawingAttributes>
<DrawingAttributes Width="7" Height="7" Color="Purple" />
</InkCanvas.DefaultDrawingAttributes>
</InkCanvas>
</Window>

I say "easy" in quotes because you'll have to take responsibility to draw
all your own chrome (titlebar, close button etc).

But still it's much easier than dealing with UpdateLayeredWindow() in Win32.
http://msdn2.microsoft.com/en-us/library/ms633556.aspx

AFAIK winforms doesn't offer any help for doing per-pixel alpha compositing
with UpdateLayeredWindow. As you've discovered, it only offers whole-window
opacity ala SetLayeredWindowAttributes.

WPF may or may not work for you. It's great if everything you're doing is
available natively within WPF. It's not so great if you're say, trying to
collect ink over IE or some other hosted Win32 or WinForms content or
controls.

Still, even for that kind of scenario, I've seen some people go the route
where they create a new top-level window with WPF (borderless, chromeless,
AllowsTransparency=True) to do the ink collection. They just keep its size
and position in sync with the underlying Win32/Winforms app window... messy,
but it works. :-)

HTH,
-S


"Alz" wrote:

> Hi, I am trying to create a transparent form with solid InkOverlay in C#
> using Visual Studio.
>
> I placed an inkoverlay on top of the form so I can write stuff on it.
> However, now I want to make the form transparent, but I also want the
> controls and the ink drawn on the inkoverlay to be solid. Is there a way to
> do this? I've tried to use opacity, but that just makes everything
> transparent. I've tried a few other things such as attaching the overlay to
> a panel, setting the transparencyKey, etc, but nothing works. Any help would
> be appreciated =).
>
> Thanks!