Declarationproperty PolylineClosingMode : TIEPolylineClosingMode;
Specifies whether a polyline is automatically closed (i.e. ObjPolylineClosed
becomes true) after the user completes insertion of it, and thus becomes a polygon.
The default of iecmManual means that it only closes if you explicitly call ObjPolylineClosed
=True. iecmAlways means it always closes. With iecmOnNearFinish it will close if the end position of the polyline is very close to the start.