<Edit>
It turns out it wasn’t externalizing the WPF control that solved the issue, but rather changing my build configuration to Release instead of Debug. When I added the externalized assembly, I set the configuration to Release. I’m not sure exactly why a debug build would cause this behavior…
</Edit>
<Edit 2>
It seems to work properly on Windows XP regardless of the build configuration. Might be a Windows 7 thing…
</Edit 2>
I’ve been doing a lot of WPF work lately and a lot of it has been with WinForms interoperating with WPF. Today I noticed some odd behavior when I tried to add a WPF control to a WinForms ElementHost object…
Usually I put the WPF control in a separate assembly, but today I thought I didn’t need to since it was just a very simple control. Immediately I saw that the WPF control wouldn’t draw itself properly for some reason. It would only draw itself sometimes, but if i clicked on the WPF control and somehow hit a Button or ComboBox, the control would show up.
I then decided to try and put the simple control in its own assembly and that solved the problem… It looks like there’s some issues with including a WPF control in a WinForms project directly, in my case anyway. I’m using Visual Studio 2008 on Win7 x86 and if anybody else has this type of issue, try doing what I did to resolve the issue.
