Reads the DXF data of this object. 

This function is called by dxfOut() to allow the object to write its data. When overriding this function: 1) Call assertReadEnabled(). 2) Call the parent class's dxfOutFields (pFiler). 4) Use pFiler to call the OdDbDxfFiler methods to write each of the object's data items in the order they were written.