XData and Dictionaries

Use this skill when you need to attach custom data to entities or store application-level data in a drawing. Covers XData (extended entity data), the Named Object Dictionary (NOD), Extension Dictionaries, XRecords, and DBDictionary operations.

XData (Extended Entity Data)

XData attaches lightweight key-value data directly to any DBObject. Each application registers a name and gets up to 16 KB of storage per entity.

Registering an Application Name

Before writing XData, the application name must exist in the RegAppTable.

using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Runtime;