Deriving Custom Entities

AcDbEntity is the base class for all database objects having a graphical representation. AcDbEntity is derived from AcDbObject. Creating a custom entity involves the following steps.

To create a custom entity

1. Derive a custom class from AcDbEntity.
2. Override all of the necessary AcDbObject functions. (See Deriving from AcDbObject for specifics.)
3. Override the required AcDbEntity functions. (See AcDbEntity Functions to Override for specifics.)
4. Override other functions as needed to support your custom functionality.
5. If you want to support the MATCHPROP command, implement AcDbMatchProperties as a protocol extension.
6. If you want to create a custom drag sequence for your entity, implement your own version of AcEdJig.

The following sections discuss these topics in more detail.