Re: Different versions of an interface
- From: "Maarten Wiltink" <maarten@xxxxxxxxxxxxxxxxxx>
- Date: Tue, 21 Jun 2005 10:09:07 +0200
<smveloso@xxxxxxxxx> wrote in message
news:1119299783.213547.95250@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> I have the following problem: After creating a "wrapper" for a COM
> dll using the "Import Type Library" function on Delphi 6, I am unable
> to instantiate an object of a specific type. The type is a new version
> of an existing interface:
>
> The COM dll is CAPICOM.dll. The interface from which I must have an
> instance is "ISigner2", but all the methods provided in the wrapper
> return objects that are of type "ISigner".
>
> Is this a known problem ? Is there a workaround for this ?
Sounds like how backwards compatibility would have to work with
interfaces. They are _declared_ to return ISigner references and you
can't change that, but the object implementing the interface can
implement both interfaces. Just query the ISigner reference for the
ISigner2 interface.
Groetjes,
Maarten Wiltink
.
- Follow-Ups:
- Re: Different versions of an interface
- From: smveloso
- Re: Different versions of an interface
- References:
- COM: Different versions of an interface
- From: smveloso
- COM: Different versions of an interface
- Prev by Date: Re: Scaling ShowMessage()
- Next by Date: Re: Scaling ShowMessage()
- Previous by thread: COM: Different versions of an interface
- Next by thread: Re: Different versions of an interface
- Index(es):
Relevant Pages
|
