dotnet windows forms designtime: Okay, I've more info now.

I think it's a Visual Studio or Reflection bug. You can find the steps to
reproduce it here:
http://weblogs.asp.net/taganov/archive/2005/10/11/427247.aspx

Argh.

CHris

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I've got a dll project containing a set of windows forms user controls. I'm
trying to add an inherited control, but I keep getting the following error:

"Unable to load assembly '<my assembly>'. Ensure that the file is a valid
..Net Framework assembly.

Up until today I have been able to add inherited controls to my project
without an issue. A google search did not reveal much in the way of help on
this issue. Does anyone know what I should do to resolve this issue?

Thanks,
Chris

Hi Chris,
I've read your blog with interest - I am having the same problem and
finding it extremely annoying and difficult to track down. I'm not
sure its just a code thing - I can get my inheritance picker to work on
and off (seemingly randomly).

I've tried:
* Deleting "%My profile%\Application Data\Microsoft\VisualStudio\7.1"
and restarting VS - no effect
* Updating the project references path on each project to remove
incorrect paths - inheritance picker worked once then stopped
* Updating file permissions and removing read only flag from the
obj\debug folders - inheritance picker worked once then stopped
* Changing to file references rather than project references -
inheritance picker worked once then stopped
* Changing file path of projects to remove "#" character from working
folder - no effect

I've also found that sometimes I can add inherited controls to the
project which is at the top of the dependency tree (My "Common"
project) without a problem, but then the next time I try that stops
working too! GRrrrrrrrr

I'm not convinced of the cause but I find it odd that random things
seem to fix it once then it stops again. I can't believe its a file
based thing, but VS seems to be doing a lot of stuff in the background
when building a project - I have found at least 6 different cached
versions of objects on my machine - and I wonder if that is the cause.
I haven't yet tried removing projects one by one to see what effect
that has but that's my next stop.

Any other ideas? Anyone even care? Losing the will to live?

I've also now tried isolating my Common project - the same thing
happens in a solution whcich only contains a single project so it's not
just to do with cross project inheritance or implementations.

That's it - I'm joining the circus - Oh, I already have...

Spam the group? Never...

If I do a "rebuild solution" (Rebuild, not build) then the inheritance
picker gets built correctly every time (As long as I rebuild everytime
I want to add an inherited control - if I make a code change and don't
rebuild it seems to invalidate my assembly cache and the inheritance
picker once again stops working).

Unfortunately once I select the base class to inherit from I now get an
error "Unable to add reference '%BaseType%' to the current application.
Check that a different version of '%BaseType%' is not already
referenced".

Have you seen that?

I've definitely seen some wierdness going on. A day after I posted my blog,
my test project started working fine. My primary project still fails to add
inherited controls. Argh!

Chris

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