This function is useful for finding elements with attached BUIW containers.
If found, the returned interface pointer is AddRef'd; the caller should release it.
- po:The element from which to start the search.
- interfaceId:The ID of the interface for which to query the attached object.
- ppInterface:On successful return, *ppInterface contains a pointer (which has been AddRef'd) to the desired interface on the attached object of the returned element.
ITrigmlElement* ITRIGMLELEMENT_GetAncestorWith(ITrigmlElement* po, AEECLSID interfaceId, void** ppInterface);
A pointer to the nearest ancestor element whose attached object implements the given interface, or NULL if no such element exists.