[python-win32] Passing data in a windows message

[Thomas Heller]

Tim Golden schrieb:
> I'm using win32gui.PyGetBufferAddressAndLen to pass the address & length 
> of a marshalled object as the wparam / lparam of a windows message. 
> Something like this:
> 
> address, length = \
>   win32gui.PyGetBufferAddressAndLen (buffer (marshal.dumps (message)))

I guess that the argument to PyGetBufferAddressAndLen() go out of scope
here, so they may already be invalid BEFORE you call PostMessage.

> PostMessage (self.hwnd, self.WM_PROGRESS_MESSAGE, length, address)
> 
> where "message" here is actually a unicode object. At the other end, I'm 
> unpacking the message with PyGetString:
> 
> message = marshal.loads (win32gui.PyGetString (lparam, wparam))
> 

Since you used PostMessage, the message is simply posted to the thread's
message queue. You have no control when it is processed; so I fear you
must keep the posted 'object' alive even longer.