/// <summary>
        /// insert signatures
        /// </summary>
        /// <param name="dwgPath"></param>
        /// <param name="dwgNameList"></param>
        public void InsertSign(string dwgPath, List <string> dwgNameList)
        {
            AdeskAppSvr.Document doc = AdeskAppSvr.Application.DocumentManager.MdiActiveDocument;
            this.Hide();
            AdeskDBSvr.Database         CurrDB          = doc.Database;//current database
            AdeskEdIn.Editor            ed              = doc.Editor;
            AdeskEdIn.PromptPointResult prPointRes_Base = ed.GetPoint(new AdeskEdIn.PromptPointOptions("选择插入的基点"));
            AdeskEdIn.PromptPointResult prPointRes_opp  = ed.GetPoint(new AdeskEdIn.PromptPointOptions("选择基点的对角点"));
            //In order to make the signs look nicely , calculate the base point and its opposite point
            AdeskGeo.Point3d P_base = CalPoint(prPointRes_Base.Value, prPointRes_opp.Value, 0.1);
            AdeskGeo.Point3d P_opp  = CalPoint(prPointRes_Base.Value, prPointRes_opp.Value, 0.9);
            //sign's width and height
            double SignWidth  = P_opp.X - P_base.X;
            double SignHeight = P_opp.Y - P_base.Y;
            //distance between each other
            double distanceW = prPointRes_opp.Value.X - prPointRes_Base.Value.X;
            double distanceH = prPointRes_opp.Value.Y - prPointRes_Base.Value.Y;
            //scale of signature. 36 is the width of sign, and 17 is the height. you should adjust them in your condition.
            double scaleWidth  = SignWidth / 36;
            double scaleHeight = SignHeight / 17;
            //today
            string date = System.DateTime.Today.ToLocalTime().ToString().Split(' ')[0];

            try
            {
                for (int i = 0; i < dwgNameList.Count; i++)
                {
                    using (AdeskDBSvr.Database tmpdb = new AdeskDBSvr.Database(false, false))
                    {
                        //read drawing
                        tmpdb.ReadDwgFile(dwgPath + dwgNameList[i], FileShare.Read, true, null);
                        //insert it as a new block
                        AdeskDBSvr.ObjectId idBTR = CurrDB.Insert(this.ICCardList[i], tmpdb, false);

                        using (AdeskDBSvr.Transaction trans = CurrDB.TransactionManager.StartTransaction())
                        {
                            AdeskDBSvr.BlockTable       bt  = (AdeskDBSvr.BlockTable)trans.GetObject(CurrDB.BlockTableId, AdeskDBSvr.OpenMode.ForRead);
                            AdeskDBSvr.BlockTableRecord btr = (AdeskDBSvr.BlockTableRecord)trans.GetObject(bt[AdeskDBSvr.BlockTableRecord.ModelSpace], AdeskDBSvr.OpenMode.ForWrite);
                            //insert point
                            AdeskGeo.Point3d inPt = new AdeskGeo.Point3d(P_base.X, P_base.Y - i * distanceH, P_base.Z);

                            #region signature date
                            //signature date
                            AdeskDBSvr.MText                SignDate       = new AdeskDBSvr.MText();
                            AdeskDBSvr.TextStyleTable       TextStyleTB    = (AdeskDBSvr.TextStyleTable)trans.GetObject(CurrDB.TextStyleTableId, AdeskDBSvr.OpenMode.ForWrite);
                            AdeskDBSvr.TextStyleTableRecord TextStyleTBRec = new AdeskDBSvr.TextStyleTableRecord();

                            TextStyleTBRec.Font = new AdeskGra.FontDescriptor("宋体", true, false, 0, 0);
                            TextStyleTB.Add(TextStyleTBRec);
                            trans.AddNewlyCreatedDBObject(TextStyleTBRec, true);
                            //trans.Commit();

                            SignDate.TextStyle  = TextStyleTBRec.Id;
                            SignDate.Contents   = date;
                            SignDate.TextHeight = SignHeight / 2;
                            SignDate.Width      = SignWidth / 3;
                            //date's location should fit the frame
                            SignDate.Location = new AdeskGeo.Point3d((inPt.X + distanceW), (inPt.Y + 1.5 * SignDate.TextHeight), inPt.Z);
                            btr.AppendEntity(SignDate);
                            trans.AddNewlyCreatedDBObject(SignDate, true);
                            #endregion

                            try
                            {
                                //create a ref to the block
                                using (AdeskDBSvr.BlockReference bref = new AdeskDBSvr.BlockReference(inPt, idBTR))
                                {
                                    bref.ScaleFactors = new AdeskGeo.Scale3d(scaleWidth, scaleHeight, 1.0);
                                    btr.AppendEntity(bref);
                                    trans.AddNewlyCreatedDBObject(bref, true);
                                }
                                trans.Commit();
                            }
                            catch (System.Exception err)
                            {
                                MessageBox.Show("one: " + err.Message);
                            }
                        }
                    }
                }
            }
            catch (Autodesk.AutoCAD.Runtime.Exception err)
            {
                MessageBox.Show("insert: " + err.Message);
            }
            this.Show();
        }