如何在python中从dll加载带有自定义接口的COM对象？

大家好。 任务是使用从dll加载的COM对象（禁止使用regsvr32）。该对象还公开了我将来需要的DirectShow接口

然后，我尝试使用来自的示例获取一个模块，我遇到了一个问题：pythoncom对DirectShow接口一无所知（例如IBaseFilter）。我的印象是pythoncom不支持定制COM接口，但那是在2008年，也许现在情况已经改变了

代码是

# -*- coding: utf-8 -*-
import ctypes, inspect, os, pythoncom, sys
from comtypes import client
from ctypes import OleDLL, c_long, byref
from uuid import UUID

#dshow is a module with DirectShow constants, etc
cmd_subfolder = os.path.realpath(os.path.abspath(os.path.join(os.path.split(inspect.getfile( inspect.currentframe() ))[0],"path_to_dshow_module")))
if cmd_subfolder not in sys.path:
    sys.path.insert(0, cmd_subfolder)
import dshow

#that way comtypes gets to know about DirectShow interfaces
qedit = client.GetModule("qedit.dll") 
dll_path = os.path.join(cmd_subfolder, "../my_path/my_dshow_filter.ax") #specifying path to dll
iid_interface = dshow.CLSID_IUnknown
iid_ibasefilter = dshow.CLSID_IBaseFilter
clsid_class = UUID(dshow.CLSID_my_filter).bytes_le
iclassfactory = UUID(str(pythoncom.IID_IClassFactory)).bytes_le
com_classfactory = c_long(0)

my_dll = ctypes.oledll.LoadLibrary(dll_path)
#getting com_classfactory pointer to an adress of IClassFactory within loaded dll
hr = my_dll.DllGetClassObject(clsid_class, iclassfactory, byref(com_classfactory))
#creating class factory from adress using pythoncom
MyFactory = pythoncom.ObjectFromAddress(com_classfactory.value, pythoncom.IID_IClassFactory)
#creating COM object using IClassFactory::CreateInstance, using IUnknown as a default interface
dmx_interface = MyFactory.CreateInstance(None, iid_interface)
# I could've tried to use IBaseFilter directly, 
# but pythoncom knows nothing about DirectShow interfaces!
# dmx = dmx_interface.QueryInterface(str(qedit.IBaseFilter._iid_)) #that yields an error
dmx = dmx_interface.QueryInterface(iid_ibasefilter) #that yields the same error

我得到的错误是

TypeError：没有注册的接口对象支持此IID

，这是可以理解的

所以，comtypes知道这一点！但不幸的是，我找不到使用comtypes甚至ctypes从dll加载COM对象的方法

---

我已经处理这个问题好几天了，我真的非常感谢你的建议。

最后，我做了一些指针操作，但我做到了

我已经从comtypes.server导入了类IClassFactory，并为它获取了一个指针（指针№1). 之后，我获得了一个c_长指针，指向我加载的dll中的IClassFactory对象（指针№2). 最后，我指定了指针的值№2到指针№1.

from comtypes.server import IClassFactory
#same code as it was before
dll_path = os.path.join(cmd_subfolder, "../my_path/my_dshow_filter.ax")
clsid_class = UUID(dshow.CLSID_my_filter).bytes_le
#that may be replaced with other IID_IClassFactory definition
#so no pythoncom is required at all
iclassfactory = UUID(str(pythoncom.IID_IClassFactory)).bytes_le 
com_classfactory = c_long(0)
my_dll = ctypes.oledll.LoadLibrary(dll)
hr = my_dll.DllGetClassObject(clsid_class, iclassfactory, byref(com_classfactory))
ptr_icf = POINTER(IClassFactory)(com_classfactory.value) #pointer to IClassFactory
#and there we'll have a pointer to IUknown of the filter inside the dll
filter = ptr_icf.CreateInstance() 
dec = filter.QueryInterface(qedit.IBaseFilter) 
filter_graph.AddFilter(dec, "dec")
#Voila!

---

因此，这项工作可以在不使用任何pythoncom的情况下完成，这对我来说是一个巨大的优势（因为之前的所有工作都是通过comtypes模块完成的）

您目前知道一种直接从ctypes完成的方法吗？具体来说，我正在尝试加载