How can I go about hosting flash content inside a WPF form and still use transparency/alpha on my WPF window? Hosting a WinForms flash controls does not allow this.
Can you use Expression to convert the flash content to XAML? I believe that there are tools in there or off to the side that do this.
Although I haven't done it, you can probably use the WebBrowser control found in WPF 3.5 sp1 to wrap your Flash content within WPF. I'm not sure how the transparency will be affected though.
Unless the control you use to display the Flash content is built in WPF, you will run in to these "airspace" issues. Every display technology from Win32 to WinForms used HWNDs "under the hood", but WPF uses DirectX. The Window Manager in Windows however, still only understands HWNDs, so WPF apps have one top-level HWND-based window, and everything under that is done in DirectX (actually things like context menus and tooltips also have top-level HWNDs as well). Adam Nathan has a very good description of WPF interop in this article.