[python-win32] Callback RemQueryInterface gives E_NOINTERFACE

[Jim Bell]

It works! Thank you!  I must have missed this in my myriad iterations.  
The calls succeed and S_OK replaces E_NOINTERFACE on the wire, as expected.

For posterity, a few more notes:

I omitted the imports before, but here they are:
import win32com.client
import win32com.server
import win32com.server.util
import win32com.universal


On 2013-12-15 8:54 PM, Mark Hammond wrote:
> 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.

# Here's the working line:
# '{F8EF...}' as from EnsureModule() above...
win32com.universal.RegisterInterfaces('{F8EF...}', 0, 1, 0, [ 
'ITheirCallBack' ])


>
>>
>> # 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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>
>