To receive notifications, a DLL application must register for the notifications by object type. This registration must be done for each instance of a particular object.

For example, the file:

• DsAddinCommand.h, included in the DraftSight API COM native C++ interface add-in template, automatically registers this event:

BEGIN_SINK_MAP(CDsAddinCommand)
    SINK_ENTRY_EX(IDC_DSAPPLICATIONEVENT, DIID__ICommandEvents, dsCommand_ExecuteNotify_id, OnExecuteNotify)
END_SINK_MAP()

• dsAddinConnection.cpp, included in the DraftSight API C++ interface add-in template, automatically registers this event: 

RegisterCommandExecuteNotifyHook( pCmd );