Re: Subclassing CStatic - re: OnPaint()

From:

"nappy" <spam@spam.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Tue, 13 Feb 2007 20:04:57 GMT

Message-ID:

<JRoAh.76199$qO4.42479@newssvr13.news.prodigy.net>

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp> wrote in message
news:eKmMbh6THHA.5016@TK2MSFTNGP05.phx.gbl...

nappy wrote:

I am trying to create a grid class using a CStatic (picture box) and
after subclassing it does not receive the WM_PAINT message. The CStatic
is in a Cdialog. Any hints would be appreciated.

I do have the ON_WM_PAINT in teh subclass's message map and an
appropriate OnPaint function..

Make sure you have changed the control's ID to something unique, instead
of IDC_STATIC.

If that's not the problem, post the code that subclasses it and related
declarations.

--
Scott McPhillips [VC++ MVP]

Yes I called it : IDC_IR_IMAGEBOX

This is the header for the subclass:

class CGridCtrl : public CStatic
{
// Construction
public:
CGridCtrl::CGridCtrl();

// Attributes
public:

// Operations
public:

// Overrides

// Implementation
public:
virtual ~CGridCtrl();

// Generated message map functions
protected:

void OnDraw (CDC *pdc);
void OnPaint ();
BOOL OnEraseBkgnd (CDC *pDC);
void DrawIRGrid(CDC *cDC);
void DrawBkg(CDC *cDC);

int m_IR_Xpts;
int m_IR_Ypts;
int m_BlockWidth;
int m_BlockHeight;

CBitmap * m_pBmp1;
CDC m_memDC ;
CDC *m_pCdc;

DECLARE_MESSAGE_MAP()
};

I can tell the class is being instantiated by placing a debug point in the
Constructor:

BEGIN_MESSAGE_MAP(CGridCtrl, CStatic)
  ON_WM_PAINT()
  ON_WM_ERASEBKGND()
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
CGridCtrl::CGridCtrl()
{
  m_pBmp1 = NULL; // DEBUG POINT HERE>.
}

..... And here's the ONPaint()

void CGridCtrl::OnPaint ()
{
CPaintDC pdc(this); // device context for painting
OnDraw(&pdc);
}

Thanks