Called by the framework when loading or storing a control from a persistent storage representation, such as a stream or property set.
This function normally makes calls to the PX_ family of functions to load or store specific user-defined properties of an OLE control.
If Control Wizard has been used to create the OLE control project, the overridden version of this function will serialize the stock properties supported by COleControl with a call to the base class function, COleControl::DoPropExchange. As you add user-defined properties to your OLE control you will need to modify this function to serialize your new properties. For more information on serialization, see the article ActiveX Controls: Serializing.