I'd like to make an animated desktop background for Windows 7 using DirectX. I'm using C#, SlimDX and a couple of P/Invoke imports of Windows API functions. I'm not brilliant with native Windows programming, but I've had a poke around online and I believe what I need to do is either:
1) Find the handle of the window containing the dekstop wallpaper, hook it up to a DirectX device and draw into it.
2) Make a new output window, and insert it above the desktop wallpaper but below the desktop icons.
I've tried both these, but neither seems to work. If I navigate the Window heirarchy starting from the handle returned by GetDesktopWindow(), I can go Desktop -> WorkerW -> SHELLDLL_DefView -> SysListView32. If I hook up a DirectX device to this handle, I can draw over the entire desktop, but it also covers the icons. If I create a Windows form, set its parent to SHELLDLL_DefView using SetParent() and then use SetWindowPos to play with its Z-order I can only seem to get it to go either behind the desktop wallpaper or in front of the desktop + icons.
It looks as though the desktop wallpaper is background to the folder view containing the icons, and therefore what I am trying to do cannot work. The only solution then would be to not use the desktop for icons, or to find some alternative, e.g. overwriting the desktop then overlaying a transparent window containing a view of the contents of some folder.
Does anyone have any idea of what I should be doing, or even whether what I want to do is possible? It seems you can draw to the desktop background using the GDI (as I believe the wxSnow program does), and I've seen something similar to what I want done by VLC Media Player under Windows XP with its DirectX wallpaper mode (interestingly, I can't seem to get this option enabled on my system).
Thanks!