Delphi DLLs with Visual Basic

m...@d-m-g.demon.co.uk (Mike Watson)

Delphi Developer

Mon, 17 Jul 2000 03:00:00 GMT

Delphi DLLs with Visual Basic

Hi,

I need to write a DLL with Delphi which will have procedures
returning values using the "var" keyword. A simple (trivial)
example would be:

procedure DoubleIT(var Num: integer);
begin
Num:=Num*2
end;

No problems so far, but the DLL needs to be able to be used
with VB.

o Can VB handle passing parameters in this manner?
o Could someone post some VB code which would call the above
procedure?

Some (most) of the procedures will have records as parameters.

o How well will VB cope with this?
o And again, could someone please post some VB code to show
how this would be done.

Thanks for your help,

Mike Watson

Dave Parson

Delphi Developer

Tue, 18 Jul 2000 03:00:00 GMT

Re:Delphi DLLs with Visual Basic

Mike,
What you will need to do on the VB side is declare the function using
ByRef...
For Example:

Declare function DoubleT Lib"mydll.dll" (byref NumberIn as
integer) as integer
that will do it..
Good luck,
Dave

Mike Watson <m...@d-m-g.demon.co.uk> wrote in article
<886087446...@d-m-g.demon.co.uk>...

Quote

> Hi,

> I need to write a DLL with Delphi which will have procedures
> returning values using the "var" keyword. A simple (trivial)
> example would be:

> procedure DoubleIT(var Num: integer);
> begin
> Num:=Num*2
> end;

> No problems so far, but the DLL needs to be able to be used
> with VB.

> o Can VB handle passing parameters in this manner?
> o Could someone post some VB code which would call the above
> procedure?

> Some (most) of the procedures will have records as parameters.

> o How well will VB cope with this?
> o And again, could someone please post some VB code to show
> how this would be done.

> Thanks for your help,

> Mike Watson

Mike Wats

Delphi Developer

Fri, 21 Jul 2000 03:00:00 GMT

Re:Delphi DLLs with Visual Basic

In article <01bd2d14$b5553ce0$99c2accf@default>
dpars...@erols.com "Dave Parsons" writes:

Quote

> Mike,
> What you will need to do on the VB side is declare the function using
> ByRef...
> For Example:

> Declare function DoubleT Lib"mydll.dll" (byref NumberIn as
> integer) as integer
> that will do it..
> Good luck,
> Dave

Thanks for this, Dave.

In your example, you have the function returning a value ( the "as
integer" after the close bracket). Presumably VB will allow me to do
it like:

declare function DoubleIT lib"mydll.dll" (byref NumberIn as integer)

??

Thanks again,

Mike

Quote

> Mike Watson <m...@d-m-g.demon.co.uk> wrote in article
> <886087446...@d-m-g.demon.co.uk>...
> > Hi,

> > I need to write a DLL with Delphi which will have procedures
> > returning values using the "var" keyword. A simple (trivial)
> > example would be:

> > procedure DoubleIT(var Num: integer);
> > begin
> > Num:=Num*2
> > end;

> > No problems so far, but the DLL needs to be able to be used
> > with VB.

> > o Can VB handle passing parameters in this manner?
> > o Could someone post some VB code which would call the above
> > procedure?

> > Some (most) of the procedures will have records as parameters.

> > o How well will VB cope with this?
> > o And again, could someone please post some VB code to show
> > how this would be done.

> > Thanks for your help,

> > Mike Watson

--
Denison Mayes Group

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