PRODUCT  :  Borland C++                           NUMBER  :  1288
  VERSION  :  3.1
       OS  :  WIN
     DATE  :  October 25, 1993                         PAGE  :  1/2

    TITLE  :  Creating a C++ DLL callable from Paradox for Windows.





            Creating a C++ DLL callable from Paradox for Windows
            ====================================================

       This document describes a simple a DLL that is callable from
  within Paradox for Windows Object PAL.  It creates a single
  function MYFUNC that takes as parameters: a window handle, and a
  pointer to a string.  It then calls MessageBox to display a
  standard Windows message box which contains the string.  Included
  below are two files, PWDLL.CPP and PWDLL.DEF.  To create the DLL,
  issue the following command from a DOS prompt:

       BCC -WDE -w PWDLL.CPP

       Now create a Paradox for Windows form, and insert a button
  into it.  In the pushbutton method for the button, add the
  following code:

       uses pwdll
            MYFUNC( hWnd CWORD, msgstring CPTR ) CWORD
       enduses

       method pushbutton( var eventInfo event )
       MYFUNC( windowHandle(), "Hello from Paradox for Windows!!" )
       endmethod


  Now run the form, push the button and viola!  The magic of DLL's
  is now at your fingertips.

  //*********************************************************************
  //
  //  FILE:  PWDLL.CPP
  //

  #define STRICT
  #include <windows.h>

  // turn off name mangling for the exported functions

  #ifdef    __cplusplus
  extern "C" {
  #endif













  PRODUCT  :  Borland C++                           NUMBER  :  1288
  VERSION  :  3.1
       OS  :  WIN
     DATE  :  October 25, 1993                         PAGE  :  2/2

    TITLE  :  Creating a C++ DLL callable from Paradox for Windows.




  UINT CALLBACK _export MYFUNC( HWND, LPSTR );

  #ifdef    __cplusplus
  }
  #endif


  int FAR PASCAL LibMain( HINSTANCE, WORD, WORD, LPSTR )
  {
       return 1;
  }


  UINT CALLBACK _export MYFUNC( HWND hWnd, LPSTR msgstring )
  {
       MessageBox( hWnd, msgstring ,
                  "Info from Paradox for Windows", MB_OK );
       return 1;
  }


  //
  // FILE : PWDLL.DEF
  //

  LIBRARY        PWDLL
  DESCRIPTION    'DLL that is callable from Paradox for Windows'
  EXETYPE        WINDOWS
  CODE           PRELOAD MOVEABLE DISCARDABLE
  DATA           PRELOAD MOVEABLE SINGLE
  HEAPSIZE       8192



  DISCLAIMER: You have the right to use this technical information
  subject to the terms of the No-Nonsense License Statement that
  you received with the Borland product to which this information
  pertains.