Controling types in PythonCOM
MarkH at ActiveState.com
Tue Feb 13 18:05:15 EST 2001
pfenn at mmm.com wrote:
> I'm working with an ill behaved type library, where the ODL for a function
> specifies a variant integer, but by mucking around in Visual C++, I've
> determined that the function really needs a VT_I2. It appears that
> PythonCOM is attempting to pass a VT_I4 which causes an exception. I am
> using the makepy generated interface, and to make sure I'm doing this
> right, I'll show my code:
Well that object sucks :) It should be capable of pulling an int out of any of the variant integer types.
> from win32com.client import Dispatch
> xrf = Dispatch('XRaw.Xraw.1') # Invoked non-dynamically, right?
Assuming you have makepy pre-generated, yes.
> This is the makepy generated interface for the problem function. I tried
> changing that first (12,17) to a (2,0) after looking at some functions that
> did have shorts for parameters but that didn't help.
The 12 means VT_VARIANT. The 17 is PARAMFLAG_FOPT | PARAMFLAG_FIN
So you probably should change it to (2,1) - ie (VT_I2, PARAMFLAG_FIN). You can't specificy FTOPT with a non variant arg.
By passing (2,0) you _may_ have ended up with a byref int (as some code that sees no flags (ie, 0) gets conservative.)
> com_error: (-2147352567, 'Exception occurred.', (0, None, None, None, 0,
> -2147473646), None)
This is certainly the COM object itself raising the error, not Python.
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