C# Offset multiple object types to both sides

[c_attle]

I'm trying to finish this program that will offset multiple object types to both sides of the line, polyline, etc. It currently works for only one object type. I want it to allow all of the normal object types like the regular offset command. Any help would be greatly appreciated.

                [CommandMethod("MLO")]
                public void MapLinesOffset()
                {
                    Document doc = acApp.DocumentManager.MdiActiveDocument;
                    Editor ed = doc.Editor;
                    Database db = doc.Database;
                    Transaction tr = db.TransactionManager.StartTransaction();

                    using (tr)
                    {
                        PromptEntityOptions peOpt = new PromptEntityOptions("\nSelect object: ");
                        peOpt.AllowNone = false;
                        peOpt.SetRejectMessage("\nNo object selected");
                        peOpt.AddAllowedClass(typeof(Polyline), true);

                        // The next lines are to allow for other objects
                        // THESE ARE THE OBJECTS IM TRYING TO ADD
                        peOpt.AddAllowedClass(typeof(Circle), true);
                        peOpt.AddAllowedClass(typeof(Line), true);
                        peOpt.AddAllowedClass(typeof(Polyline2d), true);
                        peOpt.AddAllowedClass(typeof(Polyline3d), true);
                        peOpt.AddAllowedClass(typeof(Ellipse), true);
                        peOpt.AddAllowedClass(typeof(Spline), true);

                        PromptEntityResult peRes = ed.GetEntity(peOpt);
                        if (peRes.Status == PromptStatus.OK)
                        {
                            PromptDoubleOptions pdOpt = new PromptDoubleOptions("\nSpecify offset distance: ");
                            pdOpt.AllowNegative = false;
                            pdOpt.AllowNone = false;
                            pdOpt.AllowZero = false;
                            PromptDoubleResult pdRes = ed.GetDouble(pdOpt);

                            if (pdRes.Status == PromptStatus.OK)
                            {
                                Entity selEnt =
                                    (Entity)peRes.ObjectId.GetObject(
                                    OpenMode.ForRead);

                                BlockTable bt =
                                    (BlockTable)db.BlockTableId.GetObject(
                                OpenMode.ForRead);

                                BlockTableRecord btr =
                                    (BlockTableRecord)tr.GetObject(
                                    db.CurrentSpaceId, OpenMode.ForWrite);

                                Line acLine = (Line)selEnt;

                                // Offset the object in the first direction
                                foreach (Entity acEnt in acLine.GetOffsetCurves(pdRes.Value))
                                {
                                    // Add each offset object
                                    btr.AppendEntity(acEnt);
                                    tr.AddNewlyCreatedDBObject(acEnt, true);
                                }
                                // Now offset the object in the second direction
                                foreach (Entity acEnt in acLine.GetOffsetCurves(-pdRes.Value))
                                {
                                    // Add each offset object
                                    btr.AppendEntity(acEnt);
                                    tr.AddNewlyCreatedDBObject(acEnt, true);
                                }
                            }
                        }
                        tr.Commit();
                    }
                }

[Anonymous · Accepted solution]

Try casting to a curve instead of an line.

Set  the second  argument of AddAllowedClass to false so it does not have be an exact match

[c_attle]

That did the trick! Thank you for your help!!

[heavnhell]

Thanks for your question, I just need it. And I suggest that you can modify as below: 

1.Add Arc Case

peOpt.AddAllowedClass(typeof(Arc), true);

2.Change the type to base type

Line acLine = (Line)selEnt; 

var acLine = selEnt as curve;

[insmuratturna]

my solution : 

ent = (Entity)tr.GetObject(id, OpenMode.ForWrite, true);
if (ent.Id.ObjectClass.DxfName == "LWPOLYLINE" || ent.Id.ObjectClass.DxfName == "POLYLINE")
{
entc = ent.Clone() as Entity;
Polyline km = (Polyline)entc;
     foreach (Entity ntc in km.GetOffsetCurves( value))
     {

       ecs = ntc.GeometricExtents;
       btr.AppendEntity(ntc);
       tr.AddNewlyCreatedDBObject(ntc, true);
     }
}
else if (ent.Id.ObjectClass.DxfName == "CIRCLE")
{
    Circle entt = (Circle)tr.GetObject(id, OpenMode.ForWrite, true);
    Circle enta = entt.Clone() as Circle;

   btr.AppendEntity(enta);
   tr.AddNewlyCreatedDBObject(enta, true);
}