Mtext не работает в моем коде

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using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Windows.ToolPalette;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MyApp
{
    public class Attributes
    {
        [CommandMethod("NLTAG")]
        public void ListAttributes()
        {
            Document acDoc = Application.DocumentManager.MdiActiveDocument;
            Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
            Database db = HostApplicationServices.WorkingDatabase;
            Transaction tr = db.TransactionManager.StartTransaction();
            PromptPointResult ppr;
            PromptPointOptions ppo = new PromptPointOptions("");

            // Start the transaction
            try
            {
                // Build a filter list so that only
                // block references are selected
                TypedValue[] filList = new TypedValue[1] { new TypedValue((int)DxfCode.Start, "INSERT") };
                SelectionFilter filter = new SelectionFilter(filList);
                PromptSelectionOptions opts = new PromptSelectionOptions();
                opts.MessageForAdding = "Select block references: ";
                PromptSelectionResult res = ed.GetSelection(opts, filter);

                //get the coordinates from user
                ppo.Message = "\n Select the place for print output:";
                ppr = acDoc.Editor.GetPoint(ppo);
                Point3d ptstart = ppr.Value;
                ppo.UseBasePoint = true;
                ppo.BasePoint = ptstart;
                if (ppr.Status == PromptStatus.Cancel) return;
                double x = ptstart.X;
                double y = ptstart.Y;

                double z = 0;
                // Do nothing if selection is unsuccessful
                if (res.Status != PromptStatus.OK)
                    return;

                SelectionSet selSet = res.Value;
                ObjectId[] idArray = selSet.GetObjectIds();
                foreach (ObjectId blkId in idArray)
                {
                    BlockReference blkRef = (BlockReference)tr.GetObject(blkId, OpenMode.ForRead);
                    BlockTableRecord btr = (BlockTableRecord)tr.GetObject(blkRef.BlockTableRecord, OpenMode.ForRead);
                    //ed.WriteMessage( "\nBlock: " + btr.Name );

                    btr.Dispose();

                    AttributeCollection attCol = blkRef.AttributeCollection;
                    foreach (ObjectId objId in attCol)
                    {
                        MText mtext = new MText();
                        mtext.Width = 6;
                        mtext.Location = new Point3d(x, y, z);
                        AttributeReference attRef = (AttributeReference)tr.GetObject(objId, OpenMode.ForRead);

                        string str = ("\n attribute is :" + attRef.TextString);
                        ed.WriteMessage(str);

                        var entity = tr.GetObject(objId, OpenMode.ForRead);

                        mtext.Contents = "\n" + attRef;
                        attCol.AppendAttribute(attRef);
                        tr.AddNewlyCreatedDBObject(mtext, true);
                    }
                }
                tr.Commit();
            }
            catch (Autodesk.AutoCAD.Runtime.Exception ex)
            {
                ed.WriteMessage(("Exception: " + ex.Message));
            }
            finally
            {
                tr.Dispose();
            }
        }
    }
}

Что я уже пробовал:

Я пытаюсь распечатать свой вывод в моем файле dwg, но mtext не работает, вывод не отображается в файле dwg.

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