• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 734
  • Last Modified:

Using AtlAxCreateControl and unloading controls

Hi all,

I am using the ATL function AtlAxCreateControl to create an ActiveX control at run time, using my dialog box as the parent window.

My product requires a functionality that, I must also be able to unload this dynamicaly created ActiveX control at run time. By unloading , I mean , destroying the control window (if it had one) and freeing all the associated resources.

Any comments/suggestions is welcome ?

Thanks in advance

1 Solution
I'd use CAxWindow::CreateControl/Ex instead it calls AtlAxCreateControl internally and wraps it up in an easy to manipulate object
saurabh_dasguptaAuthor Commented:
Thanks for the reply. I have just managed to get hold of some code from a MSDN article titled:
"Write ActiveX Controls Using Custom Interfaces Provided by ATL 3.0"

In this article I observed that the approach should be:

(i)Creat an instance of CAxWindow
(ii)Query for the interface IAxWinHostWindow using QueryHost method of CAxWindow
(iii)Use the method CreateControl of IAxWinHostWindow to create the OLE control
(iii)Remember a reference to the IUnknown of the OLE control
(iv)When the time to unload comes, use the IOleObject::Close  method

I am still not able to understand why the OLE control pointer returned from a direct call to AtlAxCreate.. Or CAxWindow wont give me an IOleObject interface when I do a query interface ??? Wheras the IAxWinHostWindow approach is absolutely fine ...!!!


I couldn't say without further investigation but the ATL source code might hold a clue as IAxWinHostWindow is an ATL interface - it seems that as it is a wrapper then a simple QI on the interface would not work so it exposes a method that allows you to access the wrapped object - I hope this answers you question
Roshan DavisCommented:
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

PAQ'd and pts refunded

Please leave any comments here within the next seven days.


Roshan Davis
EE Cleanup Volunteer
PAQed, with points refunded (200)

E-E Admin
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now