Valued Contributor
Posts: 100
Registered: ‎05-22-2013
Message 1 of 3 (115 Views)

get connected lines

115 Views, 2 Replies
03-31-2014 04:42 AM



How do  I get all lines connected to a selected line. The lines can cross other lines ,they can share same start or end point or they can share common vertices. In all I mean to say that I want all lines connected/touching/intersecting lines to the selected line.


Thanks & Regards

Sanjay Pandey

Valued Contributor
Posts: 61
Registered: ‎11-19-2010
Message 2 of 3 (107 Views)

Re: get connected lines

03-31-2014 05:04 AM in reply to: sanjaymann
Entity.IntersectWith Method, Line is also a class derives from this abstract class
*Expert Elite*
Posts: 1,569
Registered: ‎10-08-2008
Message 3 of 3 (85 Views)

Re: get connected lines

03-31-2014 08:56 AM in reply to: sanjaymann

Change this code to your needs:

        [DllImport("accore.dll", CharSet = CharSet.Unicode,
CallingConvention = CallingConvention.Cdecl,
EntryPoint = "ads_queueexpr")]
        extern static private int ads_queueexpr(byte[] command);

        [CommandMethod("tJL", CommandFlags.Modal | CommandFlags.UsePickSet)]
        public void TestConnectedLines()
            Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;

            Editor ed = doc.Editor;

            Database db = doc.Database;

            PromptEntityOptions pso = new PromptEntityOptions("\nPick a single line to join: ");

            pso.SetRejectMessage("\nObject must be of type Line!");

            pso.AddAllowedClass(typeof(Line), false);

            PromptEntityResult res = ed.GetEntity(pso);

            if (res.Status != PromptStatus.OK) return;
            using (DocumentLock doclock = doc.LockDocument())
                using (Transaction tr = db.TransactionManager.StartTransaction())

                   Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable( "PICKFIRST",1); 
               Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable( "PEDITACCEPT",0); 
                    BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForRead) as BlockTableRecord;

                    List<ObjectId> ids = JoinLines(btr, res.ObjectId);

                    ObjectId[] lines = ids.ToArray();
                    PromptSelectionResult chres = ed.SelectImplied();
                    if (chres.Status != PromptStatus.OK)
                        ed.WriteMessage("\nNothing added in the chain!");

                    SelectionSet newset = SelectionSet.FromObjectIds(lines);

                    string handles = "";
                    foreach (SelectedObject selobj in newset)
                        Entity subent = tr.GetObject(selobj.ObjectId, OpenMode.ForWrite) as Entity;
                        string hdl=string.Format("(handent \"{0}\")",subent.Handle.ToString());
                        handles= handles + hdl + " ";
                    System.Text.UnicodeEncoding uEncode = new System.Text.UnicodeEncoding();
                 // if PEDITACCEPT is set to 1 enshort the command avoiding "_Y" argument:
                    ads_queueexpr(uEncode.GetBytes("(COMMAND \"_.PEDIT\" \"_M\"" + handles  +  "\"\"" +  "\"_Y\" \"_J\" \"\" \"\")"));


        private void SelectConnectedLines(BlockTableRecord btr, List<ObjectId> ids, ObjectId id)
            Entity en = id.GetObject(OpenMode.ForRead, false) as Entity;

            Line ln = en as Line;

            if (ln != null)

                foreach (ObjectId idx in btr)
                    Entity ex = idx.GetObject(OpenMode.ForRead, false) as Entity;

                    Line lx = ex as Line;

                    if (((ln.StartPoint == lx.StartPoint) || (ln.StartPoint == lx.EndPoint)) ||

                        ((ln.EndPoint == lx.StartPoint) || (ln.EndPoint == lx.EndPoint)))

                        if (!ids.Contains(idx))

                            SelectConnectedLines(btr, ids, idx);

        public List<ObjectId> JoinLines(BlockTableRecord btr, ObjectId id)
            List<ObjectId> ids = new List<ObjectId>();

            SelectConnectedLines(btr, ids, id);

            return ids;



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