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Further discussions on flicker free drawing

, 23 May 2003
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An article on how to solve flicker problems
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Introduction

This article aims to show some useful codes for solving flicker problems in CTreeCtrl, CListCtrl and GDI+. And it could be viewed as an extend of Keith Rule's great article "Flicker Free Drawing In MFC".

Background

The only background to this article is that you have read the great article of Keith Rule. Thanks him for his nice code. We will use the class CMemDC proposed by him.

CTreeCtrl

For a CTreeCtrl derived class, if we want to avoid flicker, we could carry out the following steps.

  • Add the file memdc.h in your project.
  • Add the line #include "memdc.h" to stdafx.h or the desired .h file.
  • Add a public CRect variable like CRect m_rectClient;
  • Add a windows message handler for WM_ERASEBKGND, WM_SIZE, and WM_PAINT.

Then we should add the code as following:

BOOL CTreeCtrl::OnEraseBkgnd(CDC* pDC) 
{
    // TODO: Add your message handler code here and/or call default
    UNUSED_ALWAYS(pDC);

    //return CTreeCtrl::OnEraseBkgnd(pDC);
    return TRUE;
}

void CTreeCtrl::OnSize(UINT nType, int cx, int cy) 
{
    CTreeCtrl::OnSize(nType, cx, cy);

    GetClientRect(m_rectClient);
}

void CTreeCtrl::OnPaint() 
{
    CPaintDC dc(this);

    // Paint to a memory device context to reduce screen flicker.
    CMemDC memDC(&dc, &m_rectClient);

    ......

    // Let the window do its default painting...
    CWnd::DefWindowProc( WM_PAINT, (WPARAM)memDC.m_hDC, 0 );
}

Then you would get flicker free effect.

CListCtrl

For a CListCtrl derived class, all of the procedures are the same expect the OnSize function should be modified as following to allow the CHeadCtrl (if in report model) to display:

void CListCtrl::OnSize(UINT nType, int cx, int cy) 
{
    CListCtrl::OnSize(nType, cx, cy);

    GetClientRect(m_rectClient);

    CHeaderCtrl* pHC;
    pHC = GetHeaderCtrl();
    if (pHC != NULL)
    {
        CRect rectHeader;
        pHC->GetItemRect( 0, &rectHeader );
        m_rectClient.top += rectHeader.bottom;
    }
}

Then you could get flicker free effect.

GDI+

I have found several articles talking about flicker free drawing in GDI+. However, I want to extend Keith Rule's code to do the same job and avoid to re-implement the double buffer mechanism with CashedBitmap. Thus I use the following method.

  • Add the file memdc.h in your project.
  • Add the line #include "memdc.h" to stdafx.h or the desired .h file.
  • Add a public CRect variable likeCRect m_rectClient; Add a windows message handler for WM_ERASEBKGND, WM_SIZE, and WM_PAINT.

Then we should add the code as following:

BOOL CView::OnEraseBkgnd(CDC* pDC) 
{
    // TODO: Add your message handler code here and/or call default
    UNUSED_ALWAYS(pDC);

    //return CView::OnEraseBkgnd(pDC);
    return TRUE;
}

void CView::OnSize(UINT nType, int cx, int cy) 
{
    CView::OnSize(nType, cx, cy);

    GetClientRect(m_rectClient);
}

void CView::OnPaint() 
{
    CPaintDC dc(this);

    // Paint to a memory device context to reduce screen flicker.
    CMemDC memDC(&dc, &m_rectClient);
    Graphics graphics(memDC);

    ......
}

Then you could get flicker free effect. This method could also do well in CScrollView. Ok, finally, there is still an interesting question left for you: which method will be faster, this method or the double buffer implemented by CashedBitmap?

History

  • Initial release 2003-05-24.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

TeleStar

China China
I am now a faculty in Engineering. But I am also a programmer who use VC from VC1.5 to VC8.0. However, now I prefer to use C# and VB.Net in my job.

Comments and Discussions

 
GeneralGDI+ PinmemberAlex Voronyansky26-Apr-09 12:19 
QuestionHow to update listview ONLY when new data is avilable? Pinmembermethod0079-May-07 14:58 
GeneralWM_PAINT Pinmembermark pinnuck3-Apr-07 12:46 
QuestionIneffective methods?? PinmemberDouglas R. Keesler29-Dec-06 18:54 
GeneralGDI+ with CMemDC slow ! PinmemberLord Darius28-May-06 1:00 
GeneralRe: GDI+ with CMemDC slow ! PinmemberTeleStar6-Sep-06 22:33 
QuestionFlickers with WS_EX_LAYOUTRTL Pinmember_Stilgar_30-Mar-06 21:16 
AnswerRe: Flickers with WS_EX_LAYOUTRTL PinmemberTeleStar6-Sep-06 22:27 
Generalwhere is the original article Pinmemberivan françois17-Jan-06 7:17 
Generalhttp://www.codeproject.com/gdi/flickerfree.asp PinmemberTeleStar27-Jan-06 13:06 
QuestionHow to use in a dialog-based app? PinmemberHawks22-Aug-05 7:52 
Answerwhy need to use CMemDC in a dialog-based app? PinmemberTeleStar22-Aug-05 18:03 
GeneralBetter code for CTreeCtrl PinsussAdam Tegen16-Aug-04 6:12 
GeneralBetter code for CListCtrl PinsussAdam Tegen16-Aug-04 5:59 
Generalyou are right, and I think that's what they do in BCG and XTPro PinmemberAI200417-Aug-04 6:44 
GeneralRe: Better code for CListCtrl PinsussAnonymous4-Mar-05 11:18 
GeneralAwesoma powa!:) Pinmemberabloy25-Aug-07 4:01 
GeneralStop Flicker Alternative PinmemberC@ssidy15-Apr-09 5:09 
QuestionReduce flicker in ListView ? Pinmember_skidrow_vn_11-Nov-03 7:34 
AnswerRe: Reduce flicker in ListView ? Pinmemberxxxyyyzzz1-Dec-03 20:01 
AnswerRe: Reduce flicker in ListView ? PinmemberEndemoniada24-Mar-04 15:49 
GeneralIf you use SetRedraw(), Pinmemberxxxyyyzzz26-Mar-04 10:38 
GeneralPossible to use with owner draw List Control Pinmembertlee4-Nov-03 10:17 
GeneralRe: Possible to use with owner draw List Control Pinmemberxxxyyyzzz4-Nov-03 11:32 
GeneralRe: Possible to use with owner draw List Control Pinmembertlee4-Nov-03 12:10 

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