You can access the ObjectARX online documentation from the AutoCAD product documentation.
The following documents are available online for the ObjectARX SDK:
- What's New in ObjectARX. Lists ObjectARX APIs that have been added for this release.
- ObjectARX Developer's Guide. Explains ObjectARX and ObjectDBX™ concepts, and provides step-by-step procedures and code examples.
- ObjectARX Reference. Documents the ObjectARX and ObjectDBX classes, member functions, global functions, namespaces, enumerations, structures, and macros.
- ObjectARX Release Notes. Describes last-minute changes and additions to ObjectARX.