Re: Queryinterface then Release fails

From:

"Fred" <not@here.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 7 Nov 2007 22:59:07 -0000

Message-ID:

<KPWdnTuv1IjX3q_anZ2dneKdnZydnZ2d@pipex.net>

Note I see that it is not a Failure, it returns the value of the reference
count, but I dont query IID_IBasicBitmapOps
anywhere else.

"Fred" <not@here.com> wrote in message
news:Ko-dnZKGgvATpa_aRVnytAA@pipex.net...

Not directly MFC but I couldn't find an appropriate group.

I am using the imaging api. and am not too familiar with COM.

As I understood it, you must release every resource obtained through
Queryinterface.
Would someone indicate why the pBasicBitmapOps->Release(); in the code
snippet below returns S_FALSE?
(the other Releases() return S_OK).

TIA

HBITMAP withImaging2 (HDC hdc, IImage *pImage)
{

IImagingFactory* pImageFactory = 0;
IBitmapImage* pBitmapImage = 0;
IBasicBitmapOps *pBasicBitmapOps = 0;

HRESULT hr;

CoInitializeEx(0, COINIT_MULTITHREADED);

HBITMAP hBitmap = 0;

   if (SUCCEEDED(CoCreateInstance(CLSID_ImagingFactory, 0,
CLSCTX_INPROC_SERVER, IID_IImagingFactory, (void**)&pImageFactory)))
   {

ImageInfo imageInfo;

pImage->GetImageInfo(&imageInfo);

if (SUCCEEDED(pImageFactory->CreateBitmapFromImage(
pImage, imageInfo.Width, imageInfo.Height,
PixelFormatDontCare, InterpolationHintDefault,
&pBitmapImage)))

{

if (SUCCEEDED(pBitmapImage->QueryInterface(IID_IBasicBitmapOps,
  (void**)&pBasicBitmapOps)))
{
  hr=pBasicBitmapOps->Release();
}

hr=pBitmapImage->Release();

}

hr=pImageFactory->Release();
  }

  CoUninitialize();

  return hBitmap;

}