public void ExcelOp(DataGridView gdv,ArrayList selHead)

        {

            if (selHead.Count==0)

            {

                MessageBox.Show("没有数据，无法导出EXCEL！");

                return;

            }

            IWorkbook excel = new HSSFWorkbook();//创建.xls文件

            ISheet sheet = excel.CreateSheet("sheet1"); //创建sheet

            IRow row = sheet.CreateRow(0);

            //创建行对象，填充表头

            row.CreateCell(0).SetCellValue("月份");

            row.CreateCell(1).SetCellValue("门\\病");

            row.CreateCell(2).SetCellValue("科别");

            row.CreateCell(3).SetCellValue("收入类别");

            row.CreateCell(4).SetCellValue("姓名");

            //写入文件 弹出文件保存

            //string DesktopPath = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);//桌面路径

            string filename = statistics_head.Text+ printDetailClass.GetUnixTime(DateTime.Now).ToString();//文件名

            SaveFileDialog saveDialog = new SaveFileDialog();

            saveDialog.DefaultExt = "xls";

            saveDialog.Filter = "Excel文件|*.xls";

            saveDialog.FileName = filename;

            saveDialog.ShowDialog();

            filename = saveDialog.FileName;

            if (filename.IndexOf(":") < 0) return; //被点了取消

            FileStream xlsfile = new FileStream(saveDialog.FileName, FileMode.Create);

            excel.Write(xlsfile);

            xlsfile.Close();

            System.Diagnostics.Process.Start(filename);

        }