КД>class CShellExt : public IShellExtInit, public IContextMenu
КД>//...
КД>STDMETHODIMP CShellExt::QueryInterface(REFIID riid, void** ppv)
КД>{
КД> *ppv = 0;

КД> if (riid == IID_IUnknown || riid == IID_IShellExtInit || riid == IID_IContextMenu)
КД> {
КД>  *ppv = this;
 
КД>  AddRef();
КД>  return(S_OK);
КД> }

КД> return (E_NOINTERFACE);
КД>}
КД>

КД>*ppv=static_cast<IContextMenu*>(this);
КД>