public void EXPTXT()
        {
            var doc = Application.DocumentManager.MdiActiveDocument;
            var db = doc.Database;
            var ed = doc.Editor;

            // selection text
            ObjectId[] dbtextIds = ed.SelectTextEntitesInModelSpace();
            foreach (ObjectId id in dbtextIds)
            {
                using (Transaction tr = db.TransactionManager.StartTransaction())
                {
                    var text = (DBText)tr.GetObject(id, OpenMode.ForWrite);
                    ObjectId[] ids = new ObjectId[1];
                    ids[0] = id;
                    ed.SetImpliedSelection(ids);
                    var tempFile = Path.Combine(Path.GetTempPath(), "Q.wmf");

                    if (File.Exists(tempFile))
                    {
                        File.Delete(tempFile);
                    }
                    ed.Command("_.WMFOUT", tempFile, "", "");
                    var viewSize = (double)Application.GetSystemVariable("VIEWSIZE");
                    var screenSize = (Point2d)Application.GetSystemVariable("SCREENSIZE");
                    double factor = viewSize * (screenSize.X / screenSize.Y);
                    var viewCtr = (Point3d)Application.GetSystemVariable("VIEWCTR");
                    //Transform viewCtr from UCS to DCS
                    Matrix3d matUCS2DCS = ed.UCS2WCS() * ed.WCS2DCS();
                    viewCtr = viewCtr.TransformBy(matUCS2DCS);
                    var p1 = new Point3d(viewCtr.X - (factor / 2.0), viewCtr.Y - (viewSize / 2.0), .0);
                    var p2 = new Point3d(viewCtr.X + (factor / 2.0), viewCtr.Y + (viewSize / 2.0), .0);
                    //Transorm p1,p2 from DCS to UCS;
                    Matrix3d matDCS2UCS = ed.DCS2WCS() * ed.WCS2UCS();
                    p1 = p1.TransformBy(matDCS2UCS);
                    p2 = p2.TransformBy(matDCS2UCS);
                    Point2d wmfinBlockPos = new Point2d(p1.X, p2.Y);
                    var tempWithOutExt = Path.Combine(Path.GetDirectoryName(tempFile),
                                                      Path.GetFileNameWithoutExtension(tempFile));
                    ed.Command("_.WMFIN", tempWithOutExt, wmfinBlockPos, "2", "", "");
                    try
                    {
                        var wmfBlock = tr.GetObject(ed.SelectLastEnt(), OpenMode.ForWrite) as BlockReference;
                        DBObjectCollection pElems = new DBObjectCollection();
                        wmfBlock?.Explode(pElems);
                        var space = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);
                        foreach (DBObject elem in pElems)
                        {
                            space.AppendEntity(elem as Entity);
                            tr.AddNewlyCreatedDBObject(elem, true);
                        }
                        //Purge unused WMFIN Block and reference
                        ObjectId wmfBtr = GetNonErasedTableRecordId(db.BlockTableId, wmfBlock.Name);
                        ObjectIdCollection blockIds = new ObjectIdCollection();
                        blockIds.Add(wmfBtr);
                        db.Purge(blockIds);
                        foreach (ObjectId oId in blockIds)
                        {
                            DBObject obj = tr.GetObject(oId, OpenMode.ForWrite);
                            obj.Erase();

                        }
                    }
                    catch (Exception ex)
                    {
                        ed.WriteMessage(ex.Message);
                    }
                    finally
                    {
                        //Erase text entity
                        text.Erase();
                        tr.Commit();
                    }
                }

            }

        }