Re: CBitmap to IPIcture.... How?

From:

"Giovanni Dicanio" <giovanni.dicanio@invalid.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sat, 2 Feb 2008 12:00:04 +0100

Message-ID:

<ObOQlrYZIHA.4028@TK2MSFTNGP06.phx.gbl>

"Jessica" <Jessica@discussions.microsoft.com> ha scritto nel messaggio
news:AE4B68E0-A47A-46E5-835F-838EB0A9D85D@microsoft.com...

I am having a CBitMap object, and I need to create an IPicture object from
it. The code which I 've written for that is shown below. Can anyone tell
me
whether or not it's correct?

HBITMAP hBmp = (HBITMAP) bmp; // bmp is CBitmap object.
HRESULT hrCreated = E_FAIL;
IPicture* pIPict = NULL;
PICTDESC pictdesc;

pictdesc.bmp.hbitmap = hBmp;
pictdesc.picType = PICTYPE_BITMAP;
pictdesc.cbSizeofstruct = sizeof (PICTDESC);

I would clear pictdesc memory before setting the fields, something like
this:

  ::ZeroMemory( &pictdesc, sizeof(pictdesc) );

then, as you wrote:

  pictdesc.cbSizeOfstruct = ...
  ...

hrCreated = OleCreatePictureIndirect(&pictdesc,
                                                    IID_IPicture,
                                                    FALSE,
                                                    (void**)&pIPict);

Did you check the return value?
Something like this:

if ( FAILED( hrCreated ) )
... error in OleLoadPictureIndirect

I tried to save the IPicute using the IPictureDisp interface, but the bmp
file created is 0 bytes. Am I missing something here?

You should check the HRESULT return value.
Moreover, did you use IPicture::SaveAsFile to save your bitmap into file?

Moreover, for image management, you may consider interesting to see also the
GDI+ API. It offers also C++ interface to manipulate and load/save images.

HTH,
Giovanni