[comtypes-users] Problem invoking method after cast -- downcast failing?

[Mike K. <mbk...@gm...>]

I'm running 0.6.0 under Python 2.6.  Source code:

***********************************************************************

from comtypes import *
from comtypes.client import *
import comtypes.gen.iTunesLib

itunes = CreateObject("iTunes.Application")
librarySource = itunes.LibrarySource
playListCollection = librarySource.Playlists
userPlayList = playListCollection.ItemByName("My Test PlayList")

if userPlayList is None:
    userPlayList = itunes.CreatePlaylist("My Test PlayList")

print userPlayList

u2 = cast(userPlayList, POINTER(comtypes.gen.iTunesLib.IITUserPlaylist))

print u2

u2.Reveal()

***********************************************************************

This fails with the following output:

<POINTER(IITPlaylist) ptr=0x2a5a24 at 1ee1940>
<POINTER(IITUserPlaylist) ptr=0x2a5a24 at 1ee18a0>
---------------------------------------------------------------------------
WindowsError                              Traceback (most recent call last)

e:\projects\Python\FetchAudio\aftp.py in <module>()
     49 print u2
     50
---> 51 u2.Reveal()
     52

WindowsError: exception: access violation reading 0x00000000


***********************************************************************


I'm trying to do something equivalent the following, which works using
win32com.client:
u2 = win32com.client.CastTo(userPlayList, 'IITUserPlaylist')

It's as if the downcast is failing.  Please advise.

   Thanks,
   Mike