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Evgeniy Balandin · Guest

Hi!

I need to make inheritance of interfaces and to reuse implementation Com1 in
Com2.
At use of such implementation there is a error (Pure virtual function
called)
at attempt of a call of a method hello2 of the interface ICom2.
If to cause a method that is direct through the index on a class a call
hello2 works.
In what there can be a problem?

Please help.

ICom1Ptr pCom1;
ICom2Ptr pCom2;

pCom1 = new CCom1();
pCom1->hello(); // call method passed

pCom2 = new CCom2();
pCom2->hello(); // call method passed
pCom2->hello2(); // call method raised error: Pure virtual function called

// Implementation CCom1 and CCom2

#include <System.hpp>
#include "systobj.h"
#include "utilcls.h"

__interface ICom1;
typedef TComInterface<ICom1> ICom1Ptr;
typedef System::DelphiInterface<ICom1> _di_ICom1;
__interface INTERFACE_UUID("{DFF1F426-EBE9-471D-9D85-B7C2D589B958}") ICom1:
public IUnknown
{
public:
virtual void hello() = 0;
};

__interface ICom2;
typedef TComInterface<ICom2> ICom2Ptr;
typedef System::DelphiInterface<ICom2> _di_ICom2;
__interface INTERFACE_UUID("{19B2E6D7-EC5F-4B0A-81BF-AB107C06B69A}") ICom2:
public ICom1
{
public:
virtual void hello2() = 0;
};

template <class Itf>
class ICom1Impl : public TInterfacedObject, public Itf
{
public:
virtual HRESULT __stdcall QueryInterface(const GUID& IID, void **Obj)
{
return TInterfacedObject::QueryInterface(IID, Obj);
}
virtual ULONG __stdcall AddRef()
{
return TInterfacedObject::_AddRef();
}
virtual ULONG __stdcall Release()
{
return TInterfacedObject::_Release();
}
virtual void hello()
{
//............
}
};

template <class Itf>
//template <class Itf>
class ICom2Impl : public ICom1Impl<Itf>
{
public:
// Implement the IDerived methods here
virtual void hello2()
{
//............
}
};

typedef ICom1Impl<ICom1> CCom1;
typedef ICom2Impl<ICom2> CCom2;

Best regals, Evgeniy Balandin