Why the timer can't work while I implement a callback for WM_PAINT in a derived class of CStatic?

Question

1.00/5 (1 vote)

See more:

Hi all!
I think maybe I find a bug of MFC. I have make a derive class of CStatic to draw a bitmap. In the main window, I create an object of the class, and implement a message-handler for WM_TIMER. Now I find that if I implement a message-handler for WM_PAINT in the derived class, the timer of main window stop working. If I commented the declaration of WM_PAINT's handler, the timer will be fine. I don't know the reason. Is this a bug of MFC? Or I need to call some other API to make the timer working correctly?
I hope someone would be kind to help me. Thx!

Posted 11-Mar-13 17:10pm

whiteclouds

Add a Solution

Comments

Sergey Alexandrovich Kryukov 11-Mar-13 23:58pm

There are too many ways to screw up things. I don't know what way was yours :-).
In many cases, it's better to use thread instead of timer...
WM_PAINT is triggered if you call Invalidate, InvalidateRegion, InvalidateRectangle...
—SA

whiteclouds 12-Mar-13 23:16pm

I'm just want to make a demo application. I am not plan to use some complex way to fix it. All I need is just to create a timer to update bitmap every some time. Now I find the correct way by myself. I can just call CWnd::OnPaint() in derived class to screw up it. Thank you!

Sergey Alexandrovich Kryukov 13-Mar-13 1:28am

That's correct, but please understand that to help you to find a problem, we would need a code sample manifesting that problem. Complex or not, it's irrelevant, but it better should be very short, which is most usually possible, and comprehensive.
Good luck,
—SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

whiteclouds · Accepted Answer · 2013-03-12T17:17:00

Solution 1

Call CWnd::OnPaint() in the message-handler of WM_PAINT of the derived class. This small problem can be fixed.

Posted 12-Mar-13 17:17pm

whiteclouds