🚀 go-pugleaf

David Morgenlender wrote:
> 
> I have to pass a 2-dimensional array as an input parameter to a COM method.
> Neither dimension is known at compile time.  The interface is derived from
> IUnknown.  The clients will be written in C++ & VB.  I already have dynamic
> 1-dimensional arrays working in both C++ & VB.  But I haven't been able to find
> any way to specify a dynamic 2-dimensional array in the .IDL file.  I can, of
> course, convert it to a 1-dimensional array as far as COM is concerned.  But I'd
> rather keep it as 2-dimensional, if possible, to keep the code more readable,
> etc.
> 
> Any ideas?
> 
> =======================================================
> Dave Morgenlender
> e-mail: dmorgen@alum.mit.edu
> =======================================================

In IDL specify just VARIANT.

Use VARIANT of type VT_ARRAY | VT_xxx. Make parray of the
VARIANT to point to a SAFEARRAY. SAFEARRAY may contain
more than one dimension.

                 JE

You can use size_is and pointer magic to represent what you want. But, I am
not sure about VB being happy about that..:-(
Something like
HRESULT Foo([out]int * size1, [out]int* size2,[out,size_is(,*size1,*size2)]
int *** arrayOfInts);
might work.. Here you are representing pointer to
arrayOfInts[*size1][*size2].. (I think ??)


--
Girish Bharadwaj [VC++/MVP].
Please Dont send email queries to me .Post them on the newsgroups.
Thank you

David Morgenlender wrote in message <36b2516d.85013812@enews.newsguy.com>...
>I have to pass a 2-dimensional array as an input parameter to a COM method.
>Neither dimension is known at compile time.  The interface is derived from
>IUnknown.  The clients will be written in C++ & VB.  I already have dynamic
>1-dimensional arrays working in both C++ & VB.  But I haven't been able to
find
>any way to specify a dynamic 2-dimensional array in the .IDL file.  I can,
of
>course, convert it to a 1-dimensional array as far as COM is concerned.
But I'd
>rather keep it as 2-dimensional, if possible, to keep the code more
readable,
>etc.
>
>Any ideas?
>
>=======================================================
>Dave Morgenlender
>e-mail: dmorgen@alum.mit.edu
>=======================================================

Girish,

>You can use size_is and pointer magic to represent what you want. But, I am
>not sure about VB being happy about that..:-(
>Something like
>HRESULT Foo([out]int * size1, [out]int* size2,[out,size_is(,*size1,*size2)]
>int *** arrayOfInts);
>might work.. Here you are representing pointer to
>arrayOfInts[*size1][*size2].. (I think ??)

Thanks.  I'll give it a try, including with VB.  Now why didn't I think of that
syntax <g>!

=======================================================
Dave Morgenlender
e-mail: dmorgen@alum.mit.edu
=======================================================

Jyrki,

>In IDL specify just VARIANT.
>
>Use VARIANT of type VT_ARRAY | VT_xxx. Make parray of the
>VARIANT to point to a SAFEARRAY. SAFEARRAY may contain
>more than one dimension.

Thanks for the suggestion.  I was hoping to avoid SAFEARRAY, because it's a pain
to use in C++.  Also, I vaguely recall running into some kind of compatibility
problem when I tried using it in the past, but I don't recall the details.
Maybe it's incompatible with an IUnknown interface.  But I might play around
with this, if I can't come up with something easier on the C++ side.

=======================================================
Dave Morgenlender
e-mail: dmorgen@alum.mit.edu
=======================================================

I also would recommend safe arrays. VB is incapable of handling
C-style arrays. As for the C++ side - you have only to write two
convertor methods between your array class and safe array...

--
===============================
Alexander Nickolov
STL Panasonic
email: agnickolov@geocities.com
===============================

David Morgenlender wrote in message
<36ba2e2a.141530911@enews.newsguy.com>...
>Jyrki,
>
>>In IDL specify just VARIANT.
>>
>>Use VARIANT of type VT_ARRAY | VT_xxx. Make parray of the
>>VARIANT to point to a SAFEARRAY. SAFEARRAY may contain
>>more than one dimension.
>
>Thanks for the suggestion.  I was hoping to avoid SAFEARRAY, because it's a
pain
>to use in C++.  Also, I vaguely recall running into some kind of
compatibility
>problem when I tried using it in the past, but I don't recall the details.
>Maybe it's incompatible with an IUnknown interface.  But I might play
around
>with this, if I can't come up with something easier on the C++ side.
>
>=======================================================
>Dave Morgenlender
>e-mail: dmorgen@alum.mit.edu
>=======================================================

"Alexander Nickolov" <agnickolov@geocities.com> wrote:

>I also would recommend safe arrays. VB is incapable of handling
>C-style arrays. As for the C++ side - you have only to write two
>convertor methods between your array class and safe array...

Actually, VB5 *IS* capable of handling C-style arrays, although it's not
documented.  I've had it working for awhile.

=======================================================
Dave Morgenlender
e-mail: dmorgen@alum.mit.edu
=======================================================