Here is a good series of articles on ObjectARX for beginners:
List is:
- Welcome
- Requirements
- Class 1 – Overview
- Class 2 – AutoCAD’s Database
- Class 3 – Application Overview
- Class 3a – Minimum application
- Class 3b – Minimum application using ARXWizard
- Class 4 – Object Lifecycle
- Class 5 – Object Management
- Class 6 – Entities
- Class 7 – Containers
- Class 8 – Selection sets
- Class 9 – Interacting with AutoCAD
- Class 10 – Using MFC
- Class 11 – Custom ObjectARX Class
- Class 12 – Deriving from AcDbObject
- Class 13 – Deriving from AcDbEntity
- Class 14 – Creating a Custom Entity (step by step)
- Lab 1 – Creating and Editing Entities
- Lab 1 – Solved
- Lab 2 – Using a MFC Dialog
- Lab 2 – Solved
- Lab 3 – Creating a custom object
- Lab 3 – Solved
- Appendix A – Debug versus Release
