Question

Either I don’t understand COM objects, either it’s all that confusing.
I frequently ‘create’ , ‘dispatch’ COM objects – either in Python, either in VB ( Obj = win32com.client.Dispatch('Visum.Visum') or Obj = CreateObject("Excel.Application") respectively).
That’s easy, obvious and everything’s fine.
But how can I:
a) connect to COM object which is already running
b) get list of running processes which are COM objects

• in VB what is the reference, and additional info on: CreateObject command. In Python it’s part of well defined, comprehensive library of win32com whereas in VB it’s just single method without reference: http://msdn.microsoft.com/en-us/library/7t9k08y5(v=vs.80).aspx

Highly confusing (COM object,server? connection, dispatching, registering??)

Thanks for claryfying
Rafal
i2

Answer 1

First of all, I would suggest reading a good introduction to COM. Personally, i think that ‘Essential COM’ by Don Box is the best book about COM. Spending a few hours with it will save you many hours later.

That being said, let’s move to your questions.

a) In order to retrieve an existing COM object from VB, you need to call GetObject function. This will only work for COM objects which are registered with Running Object Table. Excel does this, so there shouldn’t be any problems with that.

b) as Hans Passant correctly noted, this question doesn’t make sense. Processes and COM objects are completely unrelated things, except for the fact that processes host the COM objects. It is similar to asking ‘which processes are instances of class X’. However, a process can host a COM object (or many of them). These object can be alive only temporarily, so what would you expect there? Besides, many COM classes are implemented within dlls, but created instances obviously are hosted within a process – so what would you expect there?