Re: [comtypes-users] Comserver in comtypes, how to return a pointer to an interface?

[Thomas H. <th...@ct...>]

Am 02.01.2017 um 08:16 schrieb Leonard de Ruijter:
> Hello Folks,
>
> I’m new on this list and have been working with comtypes lately. My
> current project is an attempt to implement a Microsoft Remote Desktop
> Dynamic Virtual Channel in comtypes. here
> <https://blogs.technet.microsoft.com/virtualworld/2007/09/25/dynamic-virtual-channels/>
> is a relevant article.
>
> I’ve created the following typelib:
>
> import “oaidl.idl”;
> import “ocidl.idl”;
> import “tsvirtualchannels.idl”;
>
> [
> uuid(48E31041-DAFB-49AA-B07E-DEAA06E004B5),
> version(1.0),
> ]
> library NVDADVC
> {
> importlib(“stdole2.tlb”);
> [
> uuid(AB1924A9-A608-4C5B-A1CD-A5FC020559F1),
> helpstring(“TS plugin Class”)
> ]
> coclass NVDADVC
> {
> [default] interface IWTSPlugin;
> };
> };
>
> I’ve been able to register the comserver as noted in this
> <http://starship.python.net/crew/theller/comtypes/server.html>
> documentation.
>
> Now, I have to implement an Initialize method in which I have to create
> an IWTSListenerCallback interface and provide a pointer to it. I know
> how to create an object client side, but how to do this server side? Is
> the comtypes.client involved in this as well? Is there anyone who can
> help me out with this?

Short answer (no time for a longer one):

You implement a class which implements this interface, just like a
normal COM server class: derives from comtypes.COMObject, has a
_com_interfaces_ attribute which lists the supported interface(s), in
your case at least IWTSListenerCallback.

Then create an instance of this class:
inst = MyClass()

A pointer to the COM interface can be created in this way:
inst.QueryInterface(IWTSListenerCallback)
which you can use in the Initialize method.

Thomas