Re: Different Automation compatible data types lists

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Tue, 1 Jan 2008 11:31:32 -0500

Message-ID:

<ezvOGPJTIHA.5404@TK2MSFTNGP03.phx.gbl>

"sawer" <sawer@discussions.microsoft.com> wrote in message
news:F1B3DFBF-055C-4A59-B131-456990B72D14@microsoft.com

Is VT_I1 char?

Yes. I1 stands for signed 1-byte integer.

Is VT_I4 int or long?

long

In A Practical Guide Using Visual C++ and ATL book says:

The semantics of many data types are not the same under different
languages. For example, data type char under Visual C++ has no
equivalent match under VB. Data type short under Visual C++ is
equivalent to data type integer under VB. Moreover, there is no
uniform definition of data types to deal with date and currency.

So are "int" and "char" Automation compatible data types?

long and char. But not all programming languages can handle all
automation types. For example, VB has difficulty with VT_I1 (represented
as char in C++), and doesn't support any unsigned integer types (e.g.
VT_UI4).

Can i write int variable for my method parameter in oleautomation
compatible interface ?

Use long instead.
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925