AutoCAD.NET移動選定對象到指定圖層

        //根據名稱獲取圖層ObjectId，若不存在就創建該圖層
        public static ObjectId GetLayerObjectId(this Database db, string layerName)
        {
            LayerTable lt = (LayerTable)db.LayerTableId.GetObject(OpenMode.ForRead);
            if (!lt.Has(layerName))
            {
                LayerTableRecord ltr = new LayerTableRecord();
                ltr.Name = layerName;
                lt.UpgradeOpen();
                lt.Add(ltr);

                db.TransactionManager.AddNewlyCreatedDBObject(ltr, true);
                lt.DowngradeOpen();
            }
            return lt[layerName];
        }

        [CommandMethod("PostInActiveLayer")]
        public void PostInActiveLayer()
        {
            Database db = HostApplicationServices.WorkingDatabase;
            Editor ed = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Editor;
            try
            {
                using (Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.LockDocument())
                {
                    PromptSelectionOptions pso = new PromptSelectionOptions();
                    pso.MessageForAdding = "\n請選擇實體";
                    PromptSelectionResult psr = ed.GetSelection(pso);

                    if (psr.Status == PromptStatus.OK)
                    {
                        SelectionSet ss = psr.Value;
                        ObjectId[] objids = ss.GetObjectIds();
                        ObjectIdCollection objidclt = new ObjectIdCollection(objids);
                        Group grp = new Group();
                        grp.Append(objidclt);
                        grp.SetLayer(db.GetLayerObjectId("目標圖層名字"));

                        //將對象移動到當前圖層
                        //grp.SetLayer(db.Clayer);
                    }
                }
            }
            catch (System.Exception ex)
            {
                Debug.WriteLine(ex.ToString());
                ed.WriteMessage(ex.ToString());
            }
        }