Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Why the objects keep refreshing?

Posted on 1998-09-01
5
Medium Priority
?
296 Views
Last Modified: 2010-04-02
I worked along a program with the MFC library, and I added some code for Bitmap and font display in the OnDraw function. Then the program is compiled and run, but when I
resize the program. The objects inside the view just keeps
flashing/Refreshing. ls there any way that I can get around it?
Thanks
Jacky
0
Comment
Question by:whluk
5 Comments
 
LVL 1

Expert Comment

by:Andy_Keys
ID: 1171825
Look at the WM_sizing and see if this is any use
0
 
LVL 2

Expert Comment

by:duneram
ID: 1171826
alternatively display a bigger screen initially.  SetWindowPos api will let you control the size of a window.  Coupled with GetSystemMetrics(SM_CXSCREEN) AND SM_CYSCREEN you can make a window take the full screen.
0
 
LVL 6

Expert Comment

by:snoegler
ID: 1171827
Perhaps the flashing occurs because you don't process the OnEraseBkgnd() message.
If your OnPaint() function draws the entire update region (i.e. with the background),
then you may ignore the OnEraseBkgnd() message:

BOOL CMyWnd::OnEraseBkgnd()
{
  return TRUE; // Do not call the base class implementation
}
0
 
LVL 8

Accepted Solution

by:
Answers2000 earned 100 total points
ID: 1171828
The Window style for your window will include CS_HREDRAW and CS_VREDRAW which forces a redraw of the _entire_ client area if your Windows is resized (which isn't what you want) - All frames & views do this by default in MFC

The solution is to override PreCreateWindow and create your own window class for which doesn't have these styles set, something like:

BOOL CMyView::PreCreateWindow(CREATESTRUCT& cs) {

    cs.lpszClass = AfxRegisterWndClass(
      cs.style & ~(CS_HREDRAW | CS_VREDRAW)
      ) ;

    return CView::PreCreateWindow(cs)
}



0
 
LVL 8

Expert Comment

by:Answers2000
ID: 1171829
Oops I made a mistake

cs.style & ~(CS_HREDRAW | CS_VREDRAW)

should be

0
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Errors will happen. It is a fact of life for the programmer. How and when errors are detected have a great impact on quality and cost of a product. It is better to detect errors at compile time, when possible and practical. Errors that make their wa…
Written by John Humphreys C++ Threading and the POSIX Library This article will cover the basic information that you need to know in order to make use of the POSIX threading library available for C and C++ on UNIX and most Linux systems.   [s…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.
Suggested Courses

876 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question