Derived classes and base methodes ( C++)

    
void WindowObject::Create( HWND parent = 0)
{
  
HICON   hIcon;   //window icon

HCURSOR hCursor; //window cursor


this->windowClass ="test";
WNDCLASSEX wcx;    
hIcon=(HICON)LoadImage(0,IDI_APPLICATION,IMAGE_ICON,0,0,LR_SHARED);
hCursor=(HCURSOR)LoadImage(0,IDC_ARROW,IMAGE_CURSOR,0,0,LR_SHARED);
wcx.cbSize           = sizeof(WNDCLASSEX);              //byte size of WNDCLASSEX struct

wcx.style            = CS_HREDRAW|CS_VREDRAW;           //ensure wnd is always redrawn

wcx.lpfnWndProc      = (WNDPROC)WndProc;                //pointer to the Window Procedure

wcx.cbClsExtra       = 0;                               //Extra bytes for 'class' wnds

wcx.cbWndExtra       = 0;                               //Extra bytes for this wnd

wcx.hInstance        = this->aplication;                       //Application instance

wcx.hIcon            = hIcon;                           //Application icon

wcx.hCursor          = hCursor;                         //Cursor for wnd

wcx.hbrBackground    = (HBRUSH)(COLOR_BTNFACE+1);       //Background wnd colour

wcx.lpszMenuName     = NULL;                            //Name of wnd menu

wcx.lpszClassName    = this->windowClass.data();
wcx.hIconSm          = NULL;                            //Icon in top-left corner of wnd

//Register the wnd class with the Windows system

if (!RegisterClassEx(&wcx))
    {
    //Registration has failed so inform the user

    MessageBox( NULL,
                TEXT("Failed to register wnd class"),
                TEXT("ERROR"),
                MB_OK|MB_ICONERROR);
        fail=true;
        errorMsg = "";
    }
    else
    {
        this->windowStyle=WS_OVERLAPPEDWINDOW;
     GUIObject::Create(parent);
    }
}
  

The same methode in the class that the above derives from
      
 void GUIObject::Create( HWND parent = 0)
 {
 this->parent = parent;
 this->owner=CreateWindowEx(
                    this->windowExStyle,
                    this->windowClass.data(),
                    this->caption.data(),
                    this->windowStyle,
                    this->posX,
                    this->posY,
                    this->width,
                    this->height,
                    this->parent,
                    (HMENU)this->ID,
                    this->aplication,
                    reinterpret_cast<void*>(this));     //Store the object pointer for later use..

if (!this->owner)
    {
    //wnd creation has failed so inform the user  

    MessageBox( NULL,
                TEXT("Failed to create window"),
                TEXT("ERROR"), 
                MB_OK|MB_ICONERROR);
     this->fail=true;
     this->errorMsg="Failed to create window";
    }
    else
    {
     this->created=true;
    }
 }