TCollection, TCollectionItem 을 사용 해 보기 위해서 델파이 책을 보면서 빌더로 작업을 하고 있는데요.. 막히는 곳이 있네요..

/* LnchPad.h */

class TddgLaunchPad;

class TRunBtnItem : public TCollectionItem
{
.............
public:
        __fastcall TRunBtnItem(TCollection* Collection);
        __fastcall ~TRunBtnItem(void);
};

class TRunButtons : public TCollection
{
..............
public:
        __fastcall TRunButtons(TddgLaunchPad* LaunchPad);
};

class TddgLaunchPad : public TScrollBox
{
............
public:
        __fastcall TddgLaunchPad(TComponent* Owner);
        __fastcall ~TddgLaunchPad(void);
};

/* LnchPad.cpp */

/* TRunBtnItem */

__fastcall TRunBtnItem::TRunBtnItem(TCollection* Collection) : TCollectionItem(Collection)
{
  TCollectionItem::TCollectionItem(Collection);
............
}
//---------------------------------------------------------------------------

__fastcall TRunBtnItem::~TRunBtnItem(void)
{
..........
  TCollectionItem::~TCollectionItem();
}
//---------------------------------------------------------------------------

.......

/* TRunButtons */

__fastcall TRunButtons::TRunButtons(TddgLaunchPad* LaunchPad) : TCollection(TRunBtnItem)
                                                ~~~~~~~~~~~~~~~~~~~~~~~  <-- 여기하구요...
{
  TCollection::TCollection(TRunBtnItem);
           ~~~~~~~~~~~~~~~~~~~~~~~~  <-- 여기하구요...
..........
}
//---------------------------------------------------------------------------

.......

/* TddgLaunchPad */

__fastcall TddgLaunchPad::TddgLaunchPad(TComponent* Owner) : TScrollBox(Owner)
{
  TScrollBox::TScrollBox(Owner);
.....
}
//---------------------------------------------------------------------------

__fastcall TddgLaunchPad::~TddgLaunchPad(void)
{
.........
  TScrollBox::~TScrollBox();
}

위에 밑줄친 부분에서 문제가 생기네요.  TCollection::TCollection(클래스 타입); 이렇게 돼야 할것 같은데, TRunBtnItem 을 사용하니 안되는 군요..  어떻게 해야 할까요?