//IWorkbook wk = new HSSFWorkbook(); //写03的xls
            IWorkbook wk = new XSSFWorkbook();   //写07之后xlsx
            ISheet sheet = wk.CreateSheet("A1"); //创建叫A1的Sheet
            IRow row1 = sheet.CreateRow(0);      //创建第一行 
            for (int i = 0; i < 10; i++) {       //循环给单元格设置内容
                row1.CreateCell(i).SetCellValue("create" + i);
            }
            IRow row2 = sheet.CreateRow(1);
            for (int i = 0; i < 8; i++) {
                row2.CreateCell(i).SetCellValue("delete" + i);
            }
            using (FileStream fs = File.OpenWrite("1213.xlsx")) { //
                wk.Write(fs); 
            }
            MessageBox.Show("ok");