public void deleteDimension()        {            //定义数据库            Database db = HostApplicationServices.WorkingDatabase;            //获取当前文件            Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;            //获取当前命令行对象            Editor ed = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Editor;            using (Transaction trans = db.TransactionManager.StartTransaction())            {                #region 删除组                //定义组字典                DBDictionary groupDict = (DBDictionary)db.GroupDictionaryId.GetObject(OpenMode.ForRead);                //在组字典中搜索满足条件的组对象                foreach (DictionaryEntry ide in groupDict)                {                    //获取组对象                    acadGroup partGroup = (acadGroup)trans.GetObject((ObjectId)ide.Value, OpenMode.ForRead);                    //对于组名包含"PART-"或匿名组中包含实体数量为2的组进行删除动作                    if (partGroup.Name.Contains("PART-") || (partGroup.IsAnonymous && partGroup.NumEntities == 2))                    {                        //先删除组中的对象再删除组，直接删除组的话只是将组打散而已                        foreach (ObjectId id in partGroup.GetAllEntityIds())                        {                            Entity ent = (Entity)id.GetObject(OpenMode.ForWrite);                            ent.Erase();                            ent.Dispose();                        }                        partGroup.UpgradeOpen();                        partGroup.Erase(true);                        partGroup.DowngradeOpen();                    }                }                #endregion 删除组                #region 删除尺寸线                TypedValueList values = new TypedValueList();                values.Add(0, typeof(Dimension).Name);                SelectionFilter filter = new SelectionFilter(values);                PromptSelectionResult psr = ed.SelectAll(filter);                if (psr.Status == PromptStatus.OK)                {                    //Application.ShowAlertDialog(string.Format("被选中的尺寸线有{0}个！", psr.Value.Count));                    foreach (ObjectId id in psr.Value.GetObjectIds())                    {                        Entity ent = (Dimension)id.GetObject(OpenMode.ForWrite);                        ent.Erase();                        ent.Dispose();                    }                }                #endregion 删除尺寸线                trans.Commit();            }        }