[python-win32] Callback RemQueryInterface gives E_NOINTERFACE

[Mark Hammond]

On 15/12/2013 8:28 AM, Jim Bell wrote:
> I've been though all the demos and scoured the web, and am stumped. But
> I think I'm close. I have a 3rd-party .dll/.tlb. I run makepy.py and it
> works fine.  I need to pass a callback interface, which they define,
> into one of their functions. Here's where I'm stumped.
>
> gencache.EnsureModule('{F8EF...}', 0, 1, 0) # via makepy -i -v
>
> # IID defined in the 3rd-party library...
> cbIID = IID('{188....}') # valid IID of ITheirCallBack
>
> # My callback class...
> class MyCallBack:
>      _public_methods_ = [ 'GotMsg' ]
>      _com_interfaces_ = [ cbIID ] # as defined above
>
>      def GotMsg(self, msg):
>          print 'GotMsg: %s' % str(msg) # Hey!
>
> # This doesn't work: 'Library not registered'
> win32com.universal.RegisterInterfaces('{188...}', 0, 1, 0, [
> 'ITheirCallBack'])

The first param is the UUID of the typelib, not the interface.

>
> # Instantiate my callback...
> cbRaw = MyCallBack() # Works fine.
>
> # If I pass cbIID as param 2 here, I get 'No such interface supported'
> cbCom = win32com.server.util.wrap(cbRaw)

This will be due to the failing registration above.

HTH,

Mark
>
> cliObj = win32com.client.Dispatch('theirlib.Server.1') # Fine!
>
> # Crux: we make the call,
> # but Wireshark shows RemQueryInterface back to us,
> # for ITheirCallBack/cbIID,
> # and our machine returns E_NOINTERFACE
> cliObj.InitServer(cbCom) # Doesn't crash, but fails.
>
>
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