public void ChangeAlignmentLabelStyle() { PromptEntityOptions options = new PromptEntityOptions("\nSelect Alignment: "); options.SetRejectMessage("\nThe selected object is not a Alignment!"); options.AddAllowedClass(typeof(Alignment), false); PromptEntityResult pres = Active.Editor.GetEntity(options); if (pres.Status != PromptStatus.OK) { return; } using (Transaction tr = HostApplicationServices.WorkingDatabase.TransactionManager.StartTransaction()) { try { Alignment align = (Alignment)tr.GetObject(pres.ObjectId, OpenMode.ForRead); //ObjectIdCollection ids = align.GetAlignmentLabelIds(); ObjectIdCollection ids = align.GetAlignmentLabelGroupIds(); foreach (ObjectId id in ids) { AlignmentLabelGroup style = (AlignmentLabelGroup)tr.GetObject(id, OpenMode.ForRead); Active.Editor.WriteMessage("\n " + style.ToString()); //result: //Autodesk.Civil.DatabaseServices.AlignmentDesignSpeedLabelGroup //Autodesk.Civil.DatabaseServices.AlignmentGeometryPointLabelGroup //Autodesk.Civil.DatabaseServices.AlignmentMinorStationLabelGroup //Autodesk.Civil.DatabaseServices.AlignmentStationEquationLabelGroup //Autodesk.Civil.DatabaseServices.AlignmentStationLabelGroup //LabelType lblType = (LabelType)tr.GetObject(style.ObjectId, OpenMode.ForRead); //Autodesk.Civil.DatabaseServices.LabelType //LabelStylesAlignmentRoot root = (LabelStylesRoot)tr.GetObject(id, OpenMode.ForRead); } //Active.Editor.WriteMessage("\nAlignment Curve Label Style Name (before Change) : " + alignLabelStyle.Name); //// The following Style Name is specific to Tutorial DWG file - "Labels-6a.dwg" //alignLabelStyle.Name = "Design Data"; //Active.Editor.WriteMessage("\nAlignment Curve Label Style Name (after Change) : " + alignLabelStyle.Name); tr.Commit(); } catch (Autodesk.AutoCAD.Runtime.Exception ex) { Active.Editor.WriteMessage("\n Exception message :" + ex.Message); } } }