Every ActiveX designer must implement the IOleObject and IClassFactory or IClassFactory2 interfaces, and every ActiveX designer that has a visual user interface must implement IOleInPlaceObject and IOleInPlaceActiveObject.
These interfaces provide a way for the ActiveX designer to communicate with its container, support in-place activation, and create instances of itself. In addition, most designers handle events and manage properties. This chapter describes how to support these features: