[Python.NET] CLR + wxPython + OLE initialization
brian at zope.com
Sat Apr 10 23:31:59 EDT 2004
> Today I found that in my wxPython apps, adding a CLR
> import at the top of the files causes wxPython's
> mainloop to generate a warning message box which reads
> "Could not initialize OLE". Otherwise, the
> application seemed functional. I experimented with
> it, and it seems that delaying CLR-related imports
> until after the wx Mainloop has started does the
It's late, so forgive any errors in the details, but...
This has to do with Deep Voodoo (tm) regarding the CLR and
COM compartment initialization.
Essentially, whenever you use interop (marshalling to/from
native code, etc.), the CLR will have made sure that the
process has been initialized to some COM apartment state.
Because Python for .NET uses interop extensively (to join the
managed world with unmanaged CPython), by the time 'import CLR'
finishes, you will be in whatever kind of apartment the CLR deems
By your report (and my hazy memory), if you import CLR first you
are probably getting the thread initialized as MTA, and OleInitialize
probably wants the thread to either be uninitialized or initialized
Your workaround is probably as good as any - there is no real
way to change the apartment state from Python once its been
intialized (without creating a new thread and doing a lot of
things by hand, etc.), since either the CLR itself or some
specific unmanaged call (like your OleInitialize) will have
made the choice already by the time the CLR/Python layer is
Hope this helps!
Brian Lloyd brian at zope.com
V.P. Engineering 540.361.1716
Zope Corporation http://www.zope.com
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