C# 无法通过python使用COM服务事件

我在使用某些windows服务中的事件时遇到问题（我没有访问源代码的权限，我只有文档）。其中一个事件（在文档中）定义为（C#）：

其中

BarcodeScanEventHandler

：

public delegate void BarcodeScanEventHandler( Object sender, BarcodeScanEventArgs args )

让我向您展示一个最小化的示例：

import win32com.client
cls="FooService"

api = win32com.client.Dispatch(cls)

class ApiEvents:
    def OnBarcodeScanned(self, value): #doesnt matter if its OnBarcodeScanned(self) or OnBarcodeScanned(self, value1, value2)
        print(" * Barcode scanned!")

api.Initialize()
events = win32com.client.WithEvents(api, ApiEvents)

抛出错误的内容：

  File "minevents", line 14, in <module>
    events = win32com.client.WithEvents(api, ApiEvent
  File "C:\Python27\lib\site-packages\win32com\client
 WithEvents
    raise ValueError("This COM object does not suppor
ValueError: This COM object does not support events.

  File "<pyshell#5>", line 1, in <module>
    comtypes.client.ShowEvents(api)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 218, in ShowEvents
    return comtypes.client.GetEvents(source, sink=EventDumper(), interface=interface)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 193, in GetEvents
    interface = FindOutgoingInterface(source)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 62, in FindOutgoingInterface
    interface = comtypes.com_coclass_registry[clsid]._outgoing_interfaces_[0]
AttributeError: type object 'FooService' has no attribute '_outgoing_interfaces_'

但这会带来错误：

  File "minevents", line 14, in <module>
    events = win32com.client.WithEvents(api, ApiEvent
  File "C:\Python27\lib\site-packages\win32com\client
 WithEvents
    raise ValueError("This COM object does not suppor
ValueError: This COM object does not support events.

  File "<pyshell#5>", line 1, in <module>
    comtypes.client.ShowEvents(api)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 218, in ShowEvents
    return comtypes.client.GetEvents(source, sink=EventDumper(), interface=interface)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 193, in GetEvents
    interface = FindOutgoingInterface(source)
  File "C:\Python27\lib\site-packages\comtypes\client\_events.py", line 62, in FindOutgoingInterface
    interface = comtypes.com_coclass_registry[clsid]._outgoing_interfaces_[0]
AttributeError: type object 'FooService' has no attribute '_outgoing_interfaces_'

我试图调用

添加条形码扫描
：

class BarcodeScanned(object):
    def QueryInterface(self, value):
        help(value)

barcodeScanned = BarcodeScanned()
api.add_OnBarcodeScanned(barcodeScanned)

是什么让我
IUnknown
：

class IUnknown(__builtin__.object)
 |  The most basic COM interface.
 |  
 |  Each subclasses of IUnknown must define these class attributes:
 |  
 |  _iid_ - a GUID instance defining the identifier of this interface
 |  
 |  _methods_ - a list of methods for this interface.
 |  
 |  The _methods_ list must in VTable order.  Methods are specified
 |  with STDMETHOD or COMMETHOD calls.
 |  
 |  Methods defined here:
 |  
 |  AddRef(self)
 |      Increase the internal refcount by one and return it.
 |  
 |  QueryInterface(self, interface, iid=None)
 |      QueryInterface(interface) -> instance
 |  
 |  Release(self)
 |      Decrease the internal refcount by one and return it.
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __dict__
 |      dictionary for instance variables (if defined)
 |  
 |  __weakref__
 |      list of weak references to the object (if defined)
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __metaclass__ = <class 'comtypes._cominterface_meta'>
 |      Metaclass for COM interfaces.  Automatically creates high level
 |      methods from COMMETHOD lists.

类IUnknown（\uuuu内置对象）
|最基本的COM接口。
|  
|IUnknown的每个子类必须定义以下类属性：
|  
|_iid_u-定义此接口标识符的GUID实例
|  
|_methods_u-此接口的方法列表。
|  
|“方法”列表必须按VTable顺序排列。方法是指定的
|使用STDMETHOD或COMMETHOD调用。
|  
|此处定义的方法：
|  
|AddRef（self）
|将内部refcount增加1并返回它。
|  
|QueryInterface（自身、接口、iid=None）
|QueryInterface（接口）->实例
|  
|释放（自我）
|将内部refcount减少1并返回它。
|  
|  ----------------------------------------------------------------------
|此处定义的数据描述符：
|  
|_uuudict__
|实例变量字典（如果已定义）
|  
|_uuuweakref__
|对象的弱引用列表（如果已定义）
|  
|  ----------------------------------------------------------------------
|此处定义的数据和其他属性：
|  
|\uuuu元类\uuuuu=
|COM接口的元类。自动创建高级别
|来自CommMethod列表的方法。

现在我不知道该怎么办。我做错什么了吗？但您应该知道，以下所有代码都适用于
InternetExplorer.Application
。这项服务有什么问题吗？或者，如果事件将被触发，我应该如何使用方法
add_OnBarcodeScanned
调用我的python方法/类

谢谢您的时间。
好问题！你找到解决办法了吗？@Pakman根据我记忆中的情况，我进行了深入的挖掘，我编写了自己的小库来使用COM服务。最后一个猜测是COM库有问题。最后，我无法使用该库(
class IUnknown(__builtin__.object)
 |  The most basic COM interface.
 |  
 |  Each subclasses of IUnknown must define these class attributes:
 |  
 |  _iid_ - a GUID instance defining the identifier of this interface
 |  
 |  _methods_ - a list of methods for this interface.
 |  
 |  The _methods_ list must in VTable order.  Methods are specified
 |  with STDMETHOD or COMMETHOD calls.
 |  
 |  Methods defined here:
 |  
 |  AddRef(self)
 |      Increase the internal refcount by one and return it.
 |  
 |  QueryInterface(self, interface, iid=None)
 |      QueryInterface(interface) -> instance
 |  
 |  Release(self)
 |      Decrease the internal refcount by one and return it.
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __dict__
 |      dictionary for instance variables (if defined)
 |  
 |  __weakref__
 |      list of weak references to the object (if defined)
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __metaclass__ = <class 'comtypes._cominterface_meta'>
 |      Metaclass for COM interfaces.  Automatically creates high level
 |      methods from COMMETHOD lists.