cad.net DeepCloneObjects WasErased

        /// <summary>
        /// 克隆图元到块表记录
        /// </summary>
        /// <param name="objId">id数组</param>
        /// <param name="btr">块表记录,系统/某个块内</param>
        /// <returns></returns>
        public static ObjectId[] EntityClone(this ObjectId[] objId, BlockTableRecord btr)
        {
            //ObjectId[] ids = new ObjectId[objId.Length];
            var ids = new List<ObjectId>();
            if (objId != null && objId.Length > 0)
            {
                Database db = objId[0].Database;
                IdMapping mapping = new IdMapping();//id映射 
                ObjectIdCollection blockIds = new ObjectIdCollection(objId);//集合类型更改
                try
                {
                    db.DeepCloneObjects(blockIds, btr.ObjectId, mapping, false);//克隆   这句有问题  
                }
                catch (System.Exception e)
                {
                    Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;//命令栏交互 
                    ed.WriteMessage(Environment.NewLine + "\n克隆错误:" + e.Message);
                }
                foreach (var item in objId)
                {
                    ids.Add(mapping[item].Value);//获取克隆键值对(旧块名,新块名)   
                }
            }
            return ids.ToArray();
        }