Why the objects keep refreshing?

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
whlukAsked:
Who is Participating?
 
Answers2000Connect With a Mentor Commented:
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
 
Andy_KeysCommented:
Look at the WM_sizing and see if this is any use
0
 
duneramCommented:
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
 
snoeglerCommented:
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
 
Answers2000Commented:
Oops I made a mistake

cs.style & ~(CS_HREDRAW | CS_VREDRAW)

should be

0
0
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.

All Courses

From novice to tech pro — start learning today.