Mea culpa... I didn't pay enough attention to the OP's description. What I've read in the sources matches the documentation quoted by the OP - that [out] or [out,retval] parameters cause the HRESULT to be lost.
If the S_FALSE HRESULT can be taken to mean that any output parameters are invalid, it would be possible to adapt ctypes (not comtypes!) to raise an exception for S_FALSE. To me, any HRESULTs that aren't S_OK should raise exceptions, but I'm sure there are cases out there where this would be problematic. Creating a C/C++ extension (perhaps using Pyrex or Cython) to get the HRESULT if the output parameters are valid for S_FALSE is the only other solution that occurs to me. -------------------------> "These thoughts are mine alone!" <--------- Andrew MacIntyre Operations Branch tel: +61 2 6219 5356 Communications Infrastructure Division fax: +61 2 6253 3277 Australian Communications & Media Authority email: andrew.macint...@acma.gov.au http://www.acma.gov.au/ > -----Original Message----- > From: Michael Curran [mailto:m...@kulgan.net] > Sent: Thursday, 14 January 2010 10:39 AM > To: comtypes-users@lists.sourceforge.net > Subject: Re: [comtypes-users] getting successful HRESULT values from > comtypes [SEC=PERSONAL] > > Hi, > > If I understand correctly, catching COM exceptions will not work in > this case as a return value of S_FALSE does not actually cause an > exception. > > Therefore it is impossible to be able to tell the difference between > S_OK and S_FALSE. > > Only the E_* values (specifically negative HRESULTS) cause an exception. > > Mick > > > > On 14/01/2010 10:05 AM, Andrew MacIntyre wrote: > > Catch the COMError exception and inspect its attributes. > > > > -------------------------> "These thoughts are mine alone!" <--------- > > > > Andrew MacIntyre Operations Branch > > > > tel: +61 2 6219 5356 Communications Infrastructure Division > > > > fax: +61 2 6253 3277 Australian Communications & Media Authority > > > > email: andrew.macint...@acma.gov.au > > <mailto:andrew.macint...@acma.gov.au> http://www.acma.gov.au/ > > > > *From:* Allen Saunders [mailto:allenmsaund...@gmail.com] > > *Sent:* Thursday, 14 January 2010 7:23 AM > > *To:* comtypes-users@lists.sourceforge.net > > *Subject:* [comtypes-users] getting successful HRESULT values from > comtypes > > > > Calling COM methods is straightforward just like with other Python > > objects. They can be called with positional and named arguments. > > > > Arguments marked [out] or [out, retval] in the IDL are returned from > > a sucessful method call, in a tuple if there is more than one. If no > > [out] or [out, retval] arguments are present, the HRESULT returned > > by the method call is returned. When [out] or [out, retval] > > arguments are returned from a sucessful call, the HRESULT value is lost. > > > > If the COM method call fails, a COMError exception is raised, > > containing the HRESULT value. > > > > Is it true that there is no way to get a successful HRESULT from a call > > that has [out] variables? An example is a function that can timeout, it > > may return either S_OK (0) or S_FALSE (1), an the difference between the > > two is important! > > > > Is there anyway for me to retrieve that 'lost' HRESULT? > > > > If you have received this email in error, please notify the sender > > immediately and erase all copies of the email and any attachments to it. > > The information contained in this email and any attachments may be > > private, confidential and legally privileged or the subject of > > copyright. If you are not the addressee it may be illegal to review, > > disclose, use, forward, or distribute this email and/or its contents. > > > > Unless otherwise specified, the information in the email and any > > attachments is intended as a guide only and should not be relied upon as > > legal or technical advice or regarded as a substitute for legal or > > technical advice in individual cases. Opinions contained in this email > > or any of its attachments do not necessarily reflect the opinions of ACMA. > > > > > > > > ------------------------------------------------------------------------------ > > Throughout its 18-year history, RSA Conference consistently attracts the > > world's best and brightest in the field, creating opportunities for > Conference > > attendees to learn about information security's most important issues > through > > interactions with peers, luminaries and emerging and established > companies. > > http://p.sf.net/sfu/rsaconf-dev2dev > > > > > > > > _______________________________________________ > > comtypes-users mailing list > > comtypes-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/comtypes-users > > -- > Michael Curran > email/msn/jabber: m...@kulgan.net > Skype/Twitter: md_curran > > ------------------------------------------------------------------------------ > Throughout its 18-year history, RSA Conference consistently attracts the > world's best and brightest in the field, creating opportunities for Conference > attendees to learn about information security's most important issues > through > interactions with peers, luminaries and emerging and established companies. > http://p.sf.net/sfu/rsaconf-dev2dev > _______________________________________________ > comtypes-users mailing list > comtypes-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/comtypes-users If you have received this email in error, please notify the sender immediately and erase all copies of the email and any attachments to it. The information contained in this email and any attachments may be private, confidential and legally privileged or the subject of copyright. If you are not the addressee it may be illegal to review, disclose, use, forward, or distribute this email and/or its contents. Unless otherwise specified, the information in the email and any attachments is intended as a guide only and should not be relied upon as legal or technical advice or regarded as a substitute for legal or technical advice in individual cases. Opinions contained in this email or any of its attachments do not necessarily reflect the opinions of ACMA. ------------------------------------------------------------------------------ Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev _______________________________________________ comtypes-users mailing list comtypes-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/comtypes-users
