[fpc-pascal] Interface, _AddRef, _Release, etc.

[Graeme Geldenhuys]

On 14/09/2011 23:17, Marcos Douglas wrote:
> 
> procedure Run;
> var
>   f: TFoo;  // << type is class, not interface
>   o: TObj;
> begin
>   f := TFoo.Create;

This is just wrong.


> BUT, if I create my TFoo without refcount should works, right?
> So, I change my class:
> 
>   TFoo = class(TObject, IFoo)
>   private
>     FInfo: string;
>   protected
>     function QueryInterface(const iid : tguid;out obj) : longint;stdcall;
>     function _AddRef : longint;stdcall;
>     function _Release : longint;stdcall;
>   public
>     function GetInfo: string;
>     procedure SetInfo(const AValue: string);
>   end;


On a side note:
---------------
Why not simply use CORBA interfaces, then you don't need to add the
IUnknown or IInterface interface method noise to your class declaration.
CORBA interfaces are not reference counted.


eg:

unit myunit;

{$mode objfpc}{$H+}
{$interfaces corba}

interface

type

   IFoo = interface    // NOTE: No IInterface must be specified
     ['{F71A4131-E0A5-48CB-B563-7BBB079D1085}']
     function GetInfo: string;
   end;

   TFoo = class(TObject, IFoo)
     ...
   end;


Regards,
  - Graeme -

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