Transparent CStatic on Dialog with image in background

From:

maik.wiege@googlemail.com

Newsgroups:

microsoft.public.vc.mfc

Date:

Tue, 14 Aug 2007 10:38:56 -0700

Message-ID:

<1187113136.831271.24300@g4g2000hsf.googlegroups.com>

Hi everyone!

I'm developing a little program for windows mobile (think problem
should be the same for Win32) in MFC and have problems displaying a
dialog with an JPEG-image in the background and placing some
transparent CStatic's above it.
Here is what I dit:

BOOL CMyDialog::OnEraseBkgnd(CDC * pDC)
{
    BOOL bRet = CDialog::OnEraseBkgnd(pDC);

    // draw background image
    CComPtr<IImagingFactory>pFactory;
    HRESULT hr = pFactory.CoCreateInstance(CLSID_ImagingFactory);
    IImage* pImg;
    hr = pFactory->CreateImageFromFile(_T("\\myBackImage.jpg"), &pImg);
    RECT a; a.bottom = 320; a.left = 0; a.right = 240; a.top = 0;
    pImg->Draw(pDC->m_hDC, &a, NULL);

    return bRet;
}

HBRUSH CAlarmDialog::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

    if(nCtlColor==CTLCOLOR_STATIC)
    {
        m_nullBrush.CreateStockObject(NULL_BRUSH);//m_bgBrush;
        pDC->SetBkMode(TRANSPARENT);
        return m_nullBrush;
    }
    return hbr;
}

The reason why I have to use the CComPtr things is because
CImage::Load() is not supported by Windows Mobile, but this seems not
to be the problem. The image is drawn to the background, but the areas
of the static controls is not painted at all, meaning the background
of the statics show the previous dialog "behind it" and the areas
surrounding them show the correct image.
What am I missing here?

Thanks for any help!
Greetings
  Maik