Удалить форматирование символов

       public static ErrorStatus fixoGetEntity(Transaction tr, Editor ed, RXClass rx, string msg, out ObjectId id)
        {
            ErrorStatus es;
            Entity ent;
            id = ObjectId.Null;
            PromptEntityOptions peo = new PromptEntityOptions(msg);
            peo.SetRejectMessage("\nYou're missing, try again >>");
            peo.AddAllowedClass(typeof(Entity), false);
            PromptEntityResult res;
            res = ed.GetEntity(peo);
            if (res.Status != PromptStatus.OK)
                es = ErrorStatus.PointNotOnEntity;
            id = res.ObjectId;
            if (id == ObjectId.Null)
                es = ErrorStatus.NullObjectId;
            ent = tr.GetObject(id, OpenMode.ForRead, false) as Entity;
            if (ent.GetRXClass() != rx)
            {
                ed.WriteMessage("\n{0}Must be a \"{0}\" type of only!",rx.DxfName);
                es = ErrorStatus.NotThatKindOfClass;
            }
            if (ent == null)
                es = ErrorStatus.NotAnEntity;
            else es = ErrorStatus.OK;
            return es;
        }
        [CommandMethod("StripMtextFormat", "SUF", CommandFlags.UsePickSet | CommandFlags.Redraw)]
        public void StripMtextMethod()
        {
            Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
            Editor ed = doc.Editor;
            Database db = doc.Database;
            ObjectId id = ObjectId.Null;
            using (Transaction tr = db.TransactionManager.StartTransaction())
            {
                if (fixoGetEntity(tr, ed, RXClass.GetClass(typeof(MText)), "\nSelect MTEXT to strip format", out id) == ErrorStatus.OK)
                {
                    BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);

                    // get entity by direct cast
                    Entity ent = (Entity)tr.GetObject(id, OpenMode.ForRead);
                    if (id.ObjectClass.DxfName == "MTEXT")
                    {
                        MText mtx = ent as MText;
                        mtx.UpgradeOpen();
                        string newtxt = mtx.Text;
                        ed.WriteMessage("\nText: {0}\n", newtxt);
                        mtx.Contents = newtxt;
                        mtx.RecordGraphicsModified(true);

                    }

                    tr.Commit();
                }
            }
        }

Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Runtime

Namespace MTextEditing
    Public Class Commands
        <CommandMethod("SMF")> _
        Public Sub StripMTextFormatting()
            Dim doc As Document = Application.DocumentManager.MdiActiveDocument
            Dim db As Database = doc.Database
            Dim ed As Editor = doc.Editor
            ' Указываем, что можно выбрать только MText
            Dim peo As New PromptEntityOptions(vbLf & "Выберите MText для удаления форматирования: ")
            peo.SetRejectMessage(vbLf & "это не MText.")
            peo.AddAllowedClass(GetType(MText), False)
            Dim per As PromptEntityResult = ed.GetEntity(peo)
            If per.Status <> PromptStatus.OK Then
                Return
            End If

            Dim tr As Transaction = doc.TransactionManager.StartTransaction()
            Using tr
                ' Нужно открыть MText для чтения
                Dim obj As DBObject = tr.GetObject(per.ObjectId, OpenMode.ForRead, False)
                Dim mt As MText = TryCast(obj, MText)
                If mt Is Nothing Then
                    Return
                End If
                ' Создаём объект текстового редактора для MText
                Dim te As TextEditor = TextEditor.CreateTextEditor(mt)
                If te Is Nothing Then
                    Return
                End If
                ' Просто выбираем всё и удаляем форматирование
                te.SelectAll()
                te.Selection.RemoveAllFormatting()
                ' Не забываем сохранить результаты 
                te.Close(TextEditor.ExitStatus.ExitSave)
                tr.Commit()
            End Using
        End Sub
    End Class
End Namespace