Re: How to call Windows DLL from forms 6

From: DriftWood <drift_wood_at_my-deja.com>
Date: Tue, 05 Dec 2000 17:29:06 GMT
Message-ID: <90j8kn$cns$1_at_nnrp1.deja.com>

This is the most basic sample I could create and is based on a the function MYTEST in the DLL MYDLL.DLL. The MYTEST function would be defined in the C code as:

int WINAPI MyTest (char* xyz);

---

• ********************************************************* --
• This would be the calling trigger's code --
• ********************************************************* --

declare

• Parameters parm1 VARCHAR2(200) := 'Something';
• Return value rt PLS_INTEGER; begin rt := MyLib.MyFunc1( parm1 ); end;
  • ********************************************************* --
  • This would be the wrapper package header code --
  • ********************************************************* --

PACKAGE MyLib IS
  FUNCTION MyFunc1( parm1 IN OUT VARCHAR2 )

                    RETURN PLS_INTEGER;

END;

• ********************************************************* --
• This would be the wrapper package body code --
• ********************************************************* --

PACKAGE BODY MyLib IS
  lib_hndl ora_ffi.libHandleType;
  func_hndl ora_ffi.funcHandleType;

• Note that we always pass a function handle in as the first parameter FUNCTION i_MyFunc1( func_hndl IN ora_ffi.funcHandleType, parm1 IN OUT VARCHAR2 ) RETURN PLS_INTEGER;
• This pragma is identical (except the function name) for all ORA_FFI functions PRAGMA INTERFACE(C,i_MyFunc1,11265);

  FUNCTION MyFunc1( parm1 IN OUT VARCHAR2 )

                    RETURN PLS_INTEGER
  IS
    rc       PLS_INTEGER;

  BEGIN

• Note that the function handle is the first parameter in the call rc := i_MyFunc1(func_hndl, parm1); RETURN (rc); END ;

BEGIN

• Load the library ... like WinAPI LoadLibrary() lib_hndl := ora_ffi.load_library(NULL,'MYDLL.DLL');
• Register the target function ... like WinAPI GetProcAddress() func_hndl := ora_ffi.register_function (lib_hndl,'MYTEST',ora_ffi.PASCAL_STD);
• Denote the parameter list ora_ffi.register_parameter(func_hndl,ORA_FFI.C_CHAR_PTR);
• Denote the return value ora_ffi.register_return(func_hndl,ORA_FFI.C_INT); END;

I have more complete examples, but they are larger and would include a ZIP file with binaries. Email me if you want these.

--
-cheers
  DW
--------------------------------------------------------------------
"It is a kind of good deed to say well; and yet words are not deeds.
  -William Shakespeare"


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Received on Tue Dec 05 2000 - 18:29:06 CET