Creating an object in a dll & sending it to an exe file

Hi,
Im currently creating an object that inherit a base class named BaseObject, in my DLL, and Im sending it to my application using a static function declared in my application.

The problem is that the object looks corrupted when the exe receives it.

Does anyone knows what could make this problem?

Here is how my object looks like after I created it in my DLL: http://prookle.com/vbimghost.php?do=...yimg&imgid=127

Then, I pass this object using a static function.

When my application receives it, the object looks like that:
http://prookle.com/vbimghost.php?do=...yimg&imgid=126

As you can see, the data is not the same.

Here is what the BaseObject class looks like:

Code:

---

#ifndef _BaseObject
#define _BaseObject


#ifndef API_DLL
        #ifdef CORE_EXPORTS
                #define API_DLL        //__declspec(dllimport)
        #else
                #define API_DLL        __declspec(dllexport)
        #endif
#endif



#include <vector>
#include <iostream>
using namespace std;

#include "APITypes.h"

class API_DLL BaseObject;

typedef void (BaseObject::*EnterExitFn)(uint32);
typedef void (BaseObject::*StateFn)(float);

struct State
{
        EnterExitFn mEnterFn;
        StateFn                mStateFn;
        EnterExitFn        mExitFn;
        uint32                muiStateId;
};

struct Test
{
        uint32 uiId;
        float fValue;
};


class API_DLL BaseObject
{
        public:
                BaseObject(uint32 _uiObjectId);
       
                void SetStateFn(uint32 _uiStateId, StateFn _stateFn,
                                                EnterExitFn _stateEnter = NULL,
                                                EnterExitFn _stateExitFn = NULL,
                                                bool _bStopSet = false);

                void SetState(uint32 _uiState, bool _bStopSet = false);
                void Update(float _fDelta);

                uint32 GetObjectId();

                //virtual:
                virtual uint32 SendMessage(uint32 _uiMessageType, void* _messageData){return 0;};
        private:
                uint32 FindStateIndex(uint32 _uiStateId);
        protected:
                vector<State>        mvuiStates;

                uint32                        muiObjectId;
                uint32                        muiCurrentState;
                uint32                        muiLastFrameState;

                bool                        mbHasStates;
                bool                        mbCallEnterFn;
                bool                        mbCallExitFn;
};

#endif

---

Here is how I pass the object from the DLL to the application:

Code:

---



Mouse* pMouse = new Mouse(6);
APIGameObject::RegisterObject((BaseObject*) pMouse);

---

The mouse class inherit the BaseObject class. The RegisterObject function is a static function declared in the application.

When I break in the RegisterObject static function, the object in parameter looks like this: http://prookle.com/vbimghost.php?do=...yimg&imgid=126

But, when I create the mouse object, it looks like this: http://prookle.com/vbimghost.php?do=...yimg&imgid=127

Hope someone can help me out,
Steve

it seems to be a problem of function prototyping
your dll thinks that function parameters are slightly different from the actual ones, so the pointer extracted from the stack is incorrect.

How do you pass the function pointer to your dll?

Quote:

---

Originally Posted by vart

it seems to be a problem of function prototyping
your dll thinks that function parameters are slightly different from the actual ones, so the pointer extracted from the stack is incorrect.

How do you pass the function pointer to your dll?

---

You mean, the APIGameObject::RegisterObject function?

I use the same .h for both the dll & the exe file.

Here is the .h file of that APIGameObjct class:

Code:

---


#ifndef _APIGameObject
#define _APIGameObject


#ifndef API_DLL
        #ifdef CORE_EXPORTS
                #define API_DLL        //__declspec(dllimport)
        #else
                #define API_DLL        __declspec(dllexport)
        #endif
#endif

#include "BaseObject.h"
#include "Includes.h"

#ifndef CORE_EXPORTS
        #include "BaseResource.h"
        #include "ObjectsManager.h"
        #include "ResourceImageManager.h"
#else
        class BaseResource;
        class ObjectsManager;
        class ResourceImageManager;
#endif

#define GO_CURRENT 1
class API_DLL APIGameObject
{
        public:
                static void SetObjectsManager(ObjectsManager* _pObjectsManager);
                static void SetResourceImageManager(ResourceImageManager* _pResourceImageManager);

                //API:
                static void RegisterObject(BaseObject* _pObject);
                static void RegisterResource(BaseResource* _pResource);

                static uint32 SendMessage(uint32 _uiObjId, uint32 _uiMessageType, void* _messageData);
        protected:
                static ObjectsManager* mObjectsManager;
                static ResourceImageManager* mResourceImageManager;
};

#endif

---

Thanks a lot for your help,
Steve

I don't understand how dll can be linked... there is no function body available at the moment when the dll is created

Quote:

---

Originally Posted by vart

I don't understand how dll can be linked... there is no function body available at the moment when the dll is created

---

The functions are linked since I import the lib file of my application into my dll, in visual studio.

Should I link them doiing something else? Sorry, I'm new to DLLs.

Thanks a lot for your help,
Steve

I don't know this approach...
I'm using call by callBack when I need access functions from the exe in the dlls

Quote:

---

Originally Posted by vart

I don't know this approach...
I'm using call by callBack when I need access functions from the exe in the dlls

---

I think I'll try it out with callback and see how it works. http://www.codeguru.com/cpp/cpp/cpp_...le.php/c10557/

Thanks,
Steve