AutoCAD 单行文字排版

......省略一些using
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Windows;
using Autodesk.AutoCAD.Customization;
using Autodesk.AutoCAD.GraphicsInterface;
using Autodesk.AutoCAD.Internal;

using MgdAcApplication = Autodesk.AutoCAD.ApplicationServices.Application;
using MgdAcDocument = Autodesk.AutoCAD.ApplicationServices.Document;

        /// <summary>
        /// 文字排版
        /// </summary>
        [CommandMethod("sText_Sort")]
        public void sText_Sort()
        {
            Document doc = MgdAcApplication.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            Editor ed = doc.Editor;

            ObjectIdCollection ids = STools.GetSelection();
            if (ids.Count == 0) return;

            using (Transaction trans = doc.TransactionManager.StartTransaction())
            {
                BlockTable acBlkTbl;
                acBlkTbl = trans.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
                BlockTableRecord acBlkTblRec;
                acBlkTblRec = trans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;

                List<DBText> sDBTxt = new List<DBText>();
                foreach (ObjectId id in ids)
                {
                    DBText sT = trans.GetObject(id, OpenMode.ForWrite) as DBText;
                    sDBTxt.Add(sT);                    
                }
                //从上到下排序（即按点的Y值从大到小排序）
                sDBTxt.Sort(delegate(DBText txt1, DBText txt2) { return txt2.Position.Y.CompareTo(txt1.Position.Y); });

                PromptPointOptions optStr1 = new PromptPointOptions(" [垂直排版(V)/等分字距(A)]<A>:");
                optStr1.Keywords.Add("V");
                optStr1.Keywords.Add("A");
                optStr1.Keywords.Default = "A";
                optStr1.AppendKeywordsToMessage = false;
                PromptPointResult optRes = ed.GetPoint(optStr1);

                if (optRes.Status != PromptStatus.Keyword) return;

                switch (optRes.StringResult)
                {
                    case "V":

                        double sDOB = 0;
                        if (STools.IsRegisterValueExit("间距默认值"))
                        {
                            sDOB = Convert.ToDouble(STools.GetRegisterData("间距默认值"));
                        }
                        else
                        {
                            STools.WriteRegister("间距默认值", 0.67);
                            sDOB = 0.67;
                        }

                        PromptDoubleOptions optDouble = new PromptDoubleOptions(" 输入间距倍数");
                        optDouble.DefaultValue = sDOB;
                        optDouble.AllowNegative = false;
                        optDouble.AllowNone = false;
                        optDouble.AllowZero = false;
                        PromptDoubleResult resDouble = ed.GetDouble(optDouble);
                        if (resDouble.Status == PromptStatus.OK)
                        {
                            STools.WriteRegister("间距默认值", resDouble.Value);
                            sDOB = resDouble.Value;
                        }
                        else
                        {
                            return;
                        }

                        PromptPointOptions optPoint = new PromptPointOptions(" 选择起始点[回车表示最上面不动]");
                        optPoint.AllowNone = true;
                        PromptPointResult resPoint = ed.GetPoint(optPoint);

                        Point3d sBase;
                        double iOffset = 0;
                        //当默认回车时
                        if (resPoint.Value.X == 0 && resPoint.Value.Y == 0)
                        {
                            sBase = new Point3d(sDBTxt[0].Position.X, sDBTxt[0].Position.Y, sDBTxt[0].Position.Z);
                        }
                        else
                        {
                            sBase = new Point3d(resPoint.Value.X,resPoint.Value.Y,resPoint.Value.Z);
                            iOffset = resPoint.Value.X - sDBTxt[0].Position.X;
                        }
                        int i = 0;
                                                
                        foreach (DBText sText_V in  sDBTxt)
                        {
                            trans.GetObject(sText_V.ObjectId, OpenMode.ForWrite);
                            double k = sBase.Y - (1 + sDOB) * sDBTxt[0].Height * i;
                            Point3d sPoint = new Point3d(sText_V.Position.X + iOffset, k, sText_V.Position.Z);
                            //保证对齐的关键
                            sText_V.VerticalMode = TextVerticalMode.TextBase;
                            sText_V.HorizontalMode = TextHorizontalMode.TextLeft;
                            sText_V.Position = sPoint;
                            ++i;
                        }

                        break;
                    case "A":
                        Point3d maxPoint = new Point3d(sDBTxt[0].Position.X, sDBTxt[0].Position.Y, sDBTxt[0].Position.Z);
                        Point3d minPoint = new Point3d(sDBTxt[sDBTxt.Count - 1].Position.X, sDBTxt[sDBTxt.Count - 1].Position.Y, sDBTxt[sDBTxt.Count - 1].Position.Z);
                        double n = (maxPoint.Y - minPoint.Y) / (sDBTxt.Count - 1);
                        double increment = maxPoint.Y;
                        foreach (DBText sTxt in sDBTxt)
                        {
                            //下面这句是配合写入数据库的，否则Commit()可能不起作用
                            trans.GetObject(sTxt.ObjectId, OpenMode.ForWrite);
                            Point3d coorIncrement = new Point3d(sTxt.Position.X, increment, sTxt.Position.Z);
                            //保证对齐的关键
                            sTxt.VerticalMode = TextVerticalMode.TextBase;
                            sTxt.HorizontalMode = TextHorizontalMode.TextLeft;
                            sTxt.Position = coorIncrement;
                            increment -= n;
                        }
                        break;
                    default:
                        break;
                }
                trans.Commit();
            }
        }