Plugin-able application

[m]

Hi

I have read a lot of fragmentary explains of howto develop plugin-able
application under MSWin (main application + dll's as plugins). The
problem is that everything I found is fragmentary and I can't put it
together.

If you know how to develop such application please put here complete
source code. I think it will be VERY helpful for beginners like me and
for next generations ;)

Thanks in advance.
m@j3R ;)

[Karthik Kumar]

m@j3R ; wrote:

Hi

I have read a lot of fragmentary explains of howto develop plugin-able
application under MSWin (main application + dll's as plugins). The
problem is that everything I found is fragmentary and I can't put it
together.

If you know how to develop such application please put here complete
source code. I think it will be VERY helpful for beginners like me and
for next generations ;)

Thanks in advance.
m@j3R ;)

This is off-topic here. We do not discuss it here.

Probably this is more appropriate to a Windows
specific newsgroup.

--
Karthik.
' Remove _nospamplz from my email to mail me. '

[Kevin Drapel]

m@j3R ; a écrit :

Hi

I have read a lot of fragmentary explains of howto develop plugin-able
application under MSWin (main application + dll's as plugins). The
problem is that everything I found is fragmentary and I can't put it
together.

If you know how to develop such application please put here complete
source code. I think it will be VERY helpful for beginners like me and
for next generations ;)

Thanks in advance.
m@j3R ;)

This could be somehow useful :

http://www.unitedbytes.de/go.php?site=spl

[Gianni Mariani]

m@j3R ; wrote:

Hi

I have read a lot of fragmentary explains of howto develop plugin-able
application under MSWin (main application + dll's as plugins). The
problem is that everything I found is fragmentary and I can't put it
together.

If you know how to develop such application please put here complete
source code. I think it will be VERY helpful for beginners like me and
for next generations ;)

Austria C++ has a generic factory mechanism that will work with DLL's
(and dso's). You have to figure out how to load the DLL (or dso) at run
time.

[m]

> If you know how to develop such application please put here complete

source code. I think it will be VERY helpful for beginners like me and
for next generations ;)

I think I have found the solution, see below soure files in bcb6.

############ dll.cpp ###################
//---------------------------------------------------------------------------
#include <vcl.h>
#include <windows.h>
#include "MainUnit.h"
#pragma hdrstop
#pragma argsused

int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long reason, void* lpReserved)
{
return 1;
}
//---------------------------------------------------------------------------
class TriangleShape : public AbstractPolygonShape
{
public:
TriangleShape(){};
~TriangleShape(){};
virtual char* GetShapeName();
virtual char* GetShapeName2();
};

char* TriangleShape::GetShapeName()
{
return "triangle1";
}

char* TriangleShape::GetShapeName2()
{
return "triangle2";
}

extern "C" __declspec(dllexport)
void* __stdcall RegisterShape()
{
return (new TriangleShape());
}

############ END - dll.cpp #################

############ MainUnit.h ####################
//---------------------------------------------------------------------------

#ifndef MainUnitH
#define MainUnitH
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published: // IDE-managed Components
TButton *Button1;
void __fastcall Button1Click(TObject *Sender);

private: // User declarations
public: // User declarations
__fastcall TForm1(TComponent* Owner);
};

class AbstractPolygonShape
{
public:
AbstractPolygonShape(){};
~AbstractPolygonShape(){};
virtual char* GetShapeName() = 0;
virtual char* GetShapeName2() = 0;
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

############ END MainUnit.h ####################
############ MainUnit.cpp ##################
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "MainUnit.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)
{
typedef void* (__stdcall *REGFUNCADDR)();
HINSTANCE DllInstance;
REGFUNCADDR regFunc;

AbstractPolygonShape *thisShape;

DllInstance = ::LoadLibrary("dll.dll");
if(DllInstance)
{
regFunc = (REGFUNCADDR) GetProcAddress(DllInstance, "RegisterShape");
if(regFunc)
{
thisShape = (AbstractPolygonShape *) regFunc();
}
if(thisShape)
{
char* ThisShapeName =thisShape->GetShapeName();
char* ThisShapeName2=thisShape->GetShapeName2();
ShowMessage((AnsiString)ThisShapeName);
ShowMessage((AnsiString)ThisShapeName2);
delete thisShape;
}
FreeLibrary(DllInstance);
}

}
//---------------------------------------------------------------------------

############ END - MainUnit.cpp ##############