C / C++ / MFC

BOOL CMFCTesterDlg::OnEraseBkgnd(CDC* pDC)
{
    CRect rect;
    GetClientRect(&rect);
    COLORREF c1 = RGB(64, 0, 64);
    COLORREF c2 = RGB(0, 128, 128);
    for(int i = 0; i < rect.Height(); i++)
    {
        int r, g, b;
        r = GetRValue(c1) + (GetRValue(c2) - GetRValue(c1)) * i / rect.Height();
        g = GetGValue(c1) + (GetGValue(c2) - GetGValue(c1)) * i / rect.Height();
        b = GetBValue(c1) + (GetBValue(c2) - GetBValue(c1)) * i / rect.Height();
        pDC->FillSolidRect(0, i, rect.Width(), 1, RGB(r, g, b));
    }
    return TRUE;
}

Mark Salsbery
Microsoft MVP - Visual C++

karle wrote:

CPaintDC is not useful here because it calls BeginPaint / EndPaint.
Beginpaint emit's an WM_ERASEBACKGROUND.

namespace a
{
  class X
  {
  }
}

namespace b
{
  class X
  {
  }
}

main()
{
  a::X aXObj;
  b::X bXObj;
}