Hi All,
I found an interesting articla written by Rudy Velthuis on the above subject. Take a look at:
http://home.t-online.de/home/rvelthuis/cppobjs.htm
It works in Delphi like a charm. Is this possible in FPC?? I don't have FPC to hand to test it out.
Try the following code: (NB. The c++ dll was compiled using Borland C++ 5.5.1, this may not work with gcc or other compilers..)
The C++ code is a little half-arsed btw, and uses stdio.h instead of iostreams.h for no good reason.
Matt
// C++ DLL
//Start
#include <stdio.h>
class AbstractTest
{
public:
virtual void write(const char *text) = 0;
virtual void writeLn(const char *text)= 0;
virtual void free(void) = 0;
};
class TestClass: public AbstractTest
{
public:
virtual void write(const char *text){ printf(text); };
virtual void writeLn(const char *text){ printf(text, "\n"); };
virtual void free(void){ delete this; };
};#define EXTERN __declspec(dllexport) __stdcall
extern "C" AbstractTest* EXTERN NewConsole(void){
return new TestClass();}
#pragma argsused int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long \ reason, void* lpReserved) { return 1; }
//End
//Pascal Import Unit
//Start
unit testu;
interface
type
TestClass = class
private
OldSelf: TObject;
public
procedure Write(text: PChar); virtual; cdecl; abstract;
procedure WriteLn(text: PChar); virtual; cdecl; abstract;
procedure Free; virtual; cdecl; abstract;
end;
function NewConsole: TestClass; stdcall;
implementation{ $l test.obj }
function NewConsole: TestClass; external 'Test.dll';
end.
//End
//Pascal console app
//start
{$APPTYPE CONSOLE}
uses
SysUtils,
testu in 'testu.pas';
var
t: TestClass;
begin
t := NewConsole;
t.Write('hello ');
t.WriteLn('there');
readln;
end.
//End---------------------------------------------
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