In IExtenderProvider::CanExtend(), how to query (IDispatch*)pdispExtendeeObject?

Question

I've got an unmanaged, C++ VsPackage that implements an ExtenderProvider, such that the VS IDE is calling my CanExtend() method when I select the appropriate type of object in Solution Explorer.

I want to inspect the Extendee instance to determine whether or not I should provide an Extender for it.  I understand that the Extendee instance is represented by the "IDispatch* pdispExtendeeObject" argument to CanExtend(), but I'm not sure what to do with this object.  How can I determine the name of the item, as displayed in Solution Explorer?  More generally, how can I tell what properties/attributes/methods this object supports, and how can I then invoke those properties/attributes/methods?

Answer 1

This seems to be the way to determine the name of the item, as displayed in Solution Explorer:

STDMETHODIMP CIMSolnExtenderProvider::CanExtend(
	/* [in]          */ BSTR            bstrExtenderCATID, 
	/* [in]          */ BSTR            bstrExtenderName, 
	/* [in]          */ IDispatch *     pdispExtendeeObject, 
	/* [out, retval] */ VARIANT_BOOL *  pfRetval)
{
	// ...
	CComDispatchDriver cddExtendee(pdispExtendeeObject);
	CComVariant cvarName;
	hr = cddExtendee.GetPropertyByName(L"Name",&cvarName);

	// ...
};

Still not sure how I can tell what other properties/attributes/methods this object supports...