🚀 go-pugleaf

Remy, thank you for your sample, but I use BCB 5 and it seems that
MakeObjectInstance is for the version later, because in the help there is no
link.

Samir
"Remy Lebeau (TeamB)" <gambit47.no.spam@no.spam.yahoo.com> a �crit dans le
message de news:40ee651d$1@newsgroups.borland.com...
>
> "Sam" <skneife3@wanadoo.fr> wrote in message
> news:40ee3b69@newsgroups.borland.com...
>
> > The compiler refused. It seems that a class can't has
> > a callback as method, that is right ?
>
> Typically, to make a class method work as a callback, the method has to be
> declared as 'static'.  However, in this particular case, you are using a
> window procedure.  The VCL has a special function, MakeObjectInstance(),
> that can convert a non-static class method into a window procedure
callback.
> For example:
>
>     class TMyClass
>     {
>     private:
>         void* Ptr;
>     public:
>         TMyClass();
>         ~TMyClass();
>     };
>
>     TMyClass::TMyClass()
>     {
>         Ptr = MakeObjectInstance(NewWindowProc);
>         // you can use Ptr anywhere you need to assign a callback window
> procedure
>     }
>
>     TMyClass::~TMyClass()
>     {
>         FreeObjectInstance(Ptr);
>     }
>
>     void __fastcall TMyClass::NewWindowProc(TMessage &Message)
>     {
>         ...
>         Message.Result = DefWindowProc(hSomeWnd, Message.Msg,
> Message.WParam, Message.LParam);
>     }
>
>
> Gambit
>
>
>