Re: CView invalidates entire client area on scroll

From:

"AliR" <AliR@online.nospam>

Newsgroups:

microsoft.public.vc.mfc

Date:

Tue, 9 May 2006 15:37:24 -0500

Message-ID:

<4460fda4$0$23755$a8266bb1@reader.corenews.com>

That is the normal functionality. You will have to handle the scrolling
yourself, and do your own bitblting up or down and updating the scrolled
area. If you want MFC to handle the scrolling use CScrollView.

AliR.

"Jan M" <jan@acu.no-ip.com> wrote in message
news:Ox$5jB6cGHA.3712@TK2MSFTNGP03.phx.gbl...

Hi,

I have a WIN2000 application based on CWinApp, CFrameWnd, CDocument,

CView.

CView window style is WS_CHILD|WS_VISIBLE|WS_VSCROLL.

Scrolling the CView (in this case by 1 line) results in the entire client
area being invalidated not just the area uncovered by the scroll.

I am not calling Invalidate() anywhere in my code. I see a WM_ERASEBKGND
message sent (from itself) to (and handled by) the CView window after the
WM_VSCROLL and prior to the WM_PAINT. Presumably this WM_ERASEBKGND (or
whatever triggered it) is causing the entire client area to be

invalidated.

My scroll code is:

MyCView::OnVScroll()
{
...
  // Sets m_nVscrollPos and nVscrollInc

   SetScrollPos(SB_VERT, m_nVscrollPos, TRUE); // Tried FALSE
   ScrollWindow(0, -m_cyChar * nVscrollInc, NULL, NULL);
}

How can I fix it so I just have to paint the uncovered area when

scrolling?

Thanks,

Jan