Calling a dll from forms 6

Question

Hello,
Sorry, I'm brazilian and my english isn't very good...
I'm trying to call some functions from a dll invoked by a trigger on event WHEN-BUTTON-PRESSED. I make a package as this:
---- Package Spec ----
PACKAGE anserlib IS
     function autoconnect(p_connport in number) return boolean;
END;
---- Package Body ----
PACKAGE BODY anserlib IS
     libhandle ora_ffi.libHandleType;
     autoconnect_fhandle ora_ffi.funchandletype;
     setprinton_fhandle ora_ffi.funchandletype;
     setprintoff_fhandle ora_ffi.funchandletype;
     res varchar2(200);
     commport number;
     function ff_autoconnect(fhandle ora_ffi.funchandletype, p_commport in number) return boolean;
     pragma interface(C, ff_autoconnect, 11265);
     function autoconnect(p_connport in number) return boolean is
     begin
          return(ff_autoconnect(autoconnect_fhandle,p_connport));
     end;
begin
     libhandle := Ora_Ffi.Load_Library('C:\Juarez\Anser\','Anser712.dll');
     autoconnect_fhandle := ora_ffi.register_function(libhandle,'AutoConnect');
     ora_ffi.register_parameter(autoconnect_fhandle, ora_ffi.C_INT);
     ora_ffi.register_return(autoconnect_fhandle, ora_ffi.C_INT);
     setprinton_fhandle := ora_ffi.register_function(libhandle,'SetPrintOn');
     ora_ffi.register_return(setprinton_fhandle, ora_ffi.C_INT);
     setprintoff_fhandle := ora_ffi.register_function(libhandle,'SetPrintOff');
     ora_ffi.register_return(setprintoff_fhandle, ora_ffi.C_INT);
     ora_ffi.generate_foreign(libhandle, 'anser');
exception
     when ora_ffi.ffi_error then
          --message(:bloco_teste.mensagem, acknowledge);
          message(tool_err.message, acknowledge);
END;
and the trigger is:
declare
     v_res boolean;
     v_commport number;
begin
     v_commport := 3;
     v_res := anserlib.autoconnect(v_commport);
end;
When I run the form and press button appears the message (it appears in portuguese to me, maybe the text is not the same in english, but i'll try to translate):
FRM-40734: Internal Error: occours a PL/SQL error.
Someone have an idea to help me...?
Thanks vry much!!! :)

Answer 1

In my opinion this error is something like 'General Protection Fault error' in Windows. I sow this error when my DLL worked with memory incorectly or called OCI functions which don't work under Forms Runtime.
I think the problem might be caused by a mistake inside the DLL. The other problem may be that you use incorect calling conversion. For instance, the default calling conversion in Borland C Builder or Delphi is fastcall, not cdecl.
p.s.
1. Sorry for my English too :).
2.
ora_ffi.generate_foreign(libhandle, 'anser');I'm not sure what ora_ffi.generate_foreign does exactly, because I have never used it. As far as I know it isn't needed for this code. I'd recomend you to remove this line from your program.