RGB Preview Dialog

This application shows a COLORREF structure that use Slider Control to determinates your 24-bit RGB color and shows also simple way to communicate between CSliderCtrl, CEdit, and CStatic.

void CRGBDlg::OnVScroll( UINT nSBCode,
                         UINT nPos,
                         CScrollBar* pScrollBar)
{
  CSliderCtrl* pSlider = (CSliderCtrl*) pScrollBar;
  CString szColorValue;
  int i = pSlider->GetDlgCtrlID () – IDC_SLIDER1;
  // Now, nColor = current SliderPosValue
  nColor[i] = pSlider->GetPos();
  szColorValue.Format(“%d”, nColor[i]);
  SetDlgItemText(i + IDC_EDIT1, szColorValue);
  // Get a pointer to the static window.
  CStatic* pStatic = &m_ctlPaintStatic;
  pStatic->UpdateWindow();
  pStatic->Invalidate();
  CDialog::OnVScroll(nSBCode, nPos, pScrollBar);
}
// PaintST.cpp : implementation file
//
void CPaintST::OnPaint()
{
  CPaintDC dc(this); // device context for painting
  CBrush*  pOldBrush;
  GetClientRect(rcStatic);
  CBrush  brBack(m_crBkColor);
  dc.FillRect(rcStatic, &brBack);
  pOldBrush = dc.SelectObject(&brBack);
  dc.SelectObject(pOldBrush);
  // Do not call CStatic::OnPaint() for painting messages
}
BOOL CPaintST::OnEraseBkgnd(CDC* pDC)
{
  CBrush  brBackgnd;
  // Get a pointer to the parent window
  CRGBDlg* pColorDlg = (CRGBDlg*) GetParent();
  ASSERT(pColorDlg != NULL);
  // Get new color value from SliderCtrl.
  m_crBkColor = RGB ((BYTE) pColorDlg->nColor[0],
      (BYTE) pColorDlg->nColor[1],
      (BYTE) pColorDlg->nColor[2]);
  GetClientRect(rcStatic);
  brBackgnd.CreateSolidBrush(m_crBkColor);
  pDC->FillRect(rcStatic, &brBackgnd);
  return CStatic::OnEraseBkgnd(pDC);
}

Downloads

Download demo project – 40 Kb