Painting a Gradient background

Here’s a sample which draws background of a dialog with gradient colors.


BOOL CMyDlg::OnEraseBkgnd(CDC* pDC)
{
CRect rect;
GetClientRect(&rect);

TRIVERTEX vert[4] = {
{ rect.left, rect.top, 0xff00, 0xff00, 0xff00, 0 },
{ rect.right, rect.top, 0, 0xff00, 0xff00, 0 },
{ rect.right, rect.bottom, 0xff00, 0, 0xff00, 0 },
{ rect.left, rect.bottom, 0xff00, 0xff00, 0, 0 }
};

GRADIENT_TRIANGLE grad[2] = {
{ 0, 1, 2 },
{ 0, 2, 3 }
};

::GradientFill( pDC->m_hDC, vert, 4, grad, 2, GRADIENT_FILL_TRIANGLE );

return TRUE;
}

void CMyDlg::OnSize(UINT nType, int cx, int cy)
{
// To ensure the background of the whole dialog is re-drawn
Invalidate();

CDialog::OnSize(nType, cx, cy);
}