如何使用python中的dll自定义界面加载COM对象？

问题描述：

美好的一天，每个人。该任务是使用从dll加载的COM对象（禁止使用regsvr32）。此外，该对象还提供了将来需要的DirectShow接口。如何使用python中的dll自定义界面加载COM对象？

然后我试图从this link得到一个模块，我遇到了一个问题：pythoncom不知道DirectShow接口的一些东西（例如IBaseFilter）。 from this post我得到一个印象，pythoncom不'支持自定义COM接口，但那是在2008年，也许事情现在已经改变？

的代码是

# -*- 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: There is no interface object registered that supports this IID，这是可以理解的。

因此，comtypes知道该接口！但不幸的是，我找不到一种方法来从DLL加载COM对象使用comtypes或甚至ctypes。

我一直在处理这个问题好几天了，我真的很感激建议的话。

答

最后，它采取了一些指针操作，但我做到了。

我已经导入类的IClassFactory从comtypes.server和取得的指针，它（指针№1）。之后，我已经获得了一个c_long指针，它指向我加载的dll（指针№2）内的对象IClassFactory。最后，我将指针№2的值赋给指针№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，作业可能没有任何使用pythoncom，这是一个很大的优势，我（看到，因为所有的以前的工作是通过comtypes模块完成）
来完成

如何使用python中的dll自定义界面加载COM对象？

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