//2.将datatable的数据循环出来
　　　　　　  //下面代码是通过代码写入excel
            //IWorkbook wk = new HSSFWorkbook(); //写03的xls
            IWorkbook wk = new XSSFWorkbook();   //写07之后xlsx
            ISheet sheet = wk.CreateSheet("A1");
            IRow row1 = sheet.CreateRow(0);
            for (int i = 0; i < 10; i++) {
                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");
            }