aggregation question

From:

"GAK" <usfinecats@nospam.sbcglobal.net>

Newsgroups:

microsoft.public.vc.atl

Date:

Sat, 12 Apr 2008 17:45:17 -0700

Message-ID:

<OESdt#PnIHA.4480@TK2MSFTNGP03.phx.gbl>

I am having a bit of a problem with aggregating 2 atl classes CBaseOverlay
is the inner, COverlay0 is the Outer.

Everything seems to hook up ok, I can watch the creation of both classes but
when the client tries to queryinterface one of the interfaces implemented by
the inner, it fails.

class ATL_NO_VTABLE CBaseOverlay :
public CComObjectRootEx<CComSingleThreadModel>,
public CComCoClass<CBaseOverlay, &CLSID_BaseOverlay>,
public IBaseOverlay,
public IShellIconOverlayIdentifier {

.....
BEGIN_COM_MAP(CBaseOverlay)
COM_INTERFACE_ENTRY(IBaseOverlay)
COM_INTERFACE_ENTRY(IShellIconOverlayIdentifier)
END_COM_MAP()

}

for the outer

class ATL_NO_VTABLE COverlay0 :
public CComObjectRootEx<CComSingleThreadModel>,
public CComCoClass<COverlay0, &CLSID_Overlay0>,
public IOverlay0
{
.....

BEGIN_COM_MAP(COverlay0)
COM_INTERFACE_ENTRY(IOverlay0)
COM_INTERFACE_ENTRY_AGGREGATE (IID_IBaseOverlay, ptrUnk)
END_COM_MAP()

DECLARE_PROTECT_FINAL_CONSTRUCT()
DECLARE_GET_CONTROLLING_UNKNOWN()
IUnknown* ptrUnk;

HRESULT FinalConstruct()
{

    HRESULT Status = CoCreateInstance(CLSID_BaseOverlay,
GetControllingUnknown(),CLSCTX_ALL, IID_IUnknown, (void**)&ptrUnk);
    IBaseOverlay* pBO;
    ptrUnk->QueryInterface(IID_IBaseOverlay, (void**)&pBO);
    ((CBaseOverlay*)pBO)->IconIndex = 0;
    pBO->Release();
    return Status;
}

void FinalRelease()
{
   ptrUnk->Release();
}

.....
}

Any ideas what I'm missing?
--
Gak -
Finecats