The ObjectARX classes with an AcRx prefix provide system-level functionality such as DLL initialization and linking and runtime class registration and identification. The AcRxObject base class provides the following facilities:
The AcRx library also provides a set of C++ macros to help you create new ObjectARX classes derived from AcRxObject (see Deriving a Custom ObjectARX Class).
Every subclass of AcRxObject has an associated class descriptor object (of type AcRxClass) that is used for runtime type identification. ObjectARX provides functions for testing whether an object is of a particular class or derived class, functions for determining whether two objects are of the same class, and functions for returning the class descriptor object for a given class.
AcRxDictionary is another important class in this group. A dictionary is a mapping from a text string to another object. ObjectARX places its objects, classes, and service dictionaries in a global object dictionary, which is an instance of the AcRxDictionary class. Applications can add objects to this dictionary so that they are accessible to other applications.
For more information on using AcRx classes, see ObjectARX Application Basics,, Deriving a Custom ObjectARX Class, and Protocol Extension.