I could swear I've seen this work for other controls:
I've got two instances of devenv running. One has the solution containing my
custom controls. The other has the solution containing the page which uses
the custom controls (call that instance P.sln).
Now, when the custom control is modified (for instance, if I add a
property), and then built, it's natural that P.sln doesn't see the change.
But I could swear I've seen it where building the P.sln solution _does_ see
the change in the designer. Certainly if I execute the page, the new
property takes effect.
Exiting the P.sln instance and restarting devenv on that solution shows the
For other reasons, I was curious about the html being generated at
design-time, so I added "Debug.WriteLine(designTimeHtml)" to the designer
then debugged the P.sln instance from a third instance of devenv. In
addition to showing me the design-time HTML, it showed me "AppDomain:
loading Assembly.dll" messages when I did a build in the P.sln instance. I
notice that the assembly containing my custom control is _not_ reloaded at
that time, and in fact, _none_ of the out-of-solution assemblies are
Could I be doing something wrong in my control or its designer? There's only
one other thing happening at design-time which looks like it could be my
bug, and I don't see how that's related (I'll post that on another thread).
Should I be releasing something to permit devenv to release the designer
instance? I don't see that my designer is holding on to anything - it does
little more than catch exceptions in GetDesignTimeHtml and do