We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you a podcast all about Citrix Workspace, moving to the cloud, and analytics & intelligence. Episode 2 coming soon!Listen Now

x

Can't use ocx control in secondary thread

boontien
boontien asked
on
Medium Priority
401 Views
Last Modified: 2013-11-19
Hi, need some help here. I can't seem to use any ocx control (such as grid32 and crystal report control) when they are used in secondary threads.
If I use them in my main application no problem. The problem occurs when I post a thread message (using PostThreadMessage) to another user interface thread (derived using CWinThread, and is in another mfc externison dll). The dialog box that
consists the control will appear but will then crash out with access violation exception after the dialog box is closed.
The msdn knowledge base noted that this is a bug in ver 4.1 of visual c, but visual 4.2b should work. Anyone has any solution here? Thanks a lot.

Regards
Boon Tien Ng

Comment
Watch Question

Commented:
I can put here my remark. First of all I always have problems using PostThreadMessage(). Use global variables to transfer data between threads and it will work. Second, if you have access violation on closing window, that means some work in destruction of this window was done by you, and some by MFC. And there is a conflict. I do not know how you create this window, but maybe you should use pointers instead of objects, create objects and delete them explicitly. Use Destroy() on window objects.
Regards,
Commented:
Make sure you're initializing OLE from each thread you're using it in.

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.