把数据导出到的Excel文件

        public static void ExportExcel()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("<table style='1000px;'>");
            sb.Append("<tr style='background: green'><td align='center' valign='middle' colspan='4'>这是表格标题</td></tr>");
            sb.Append("<tr style='border:1px solid yellow'><th style='200px'>t1</th><th style='500px'>t2</th><th colspan='2' style='300px'>t3t4</th></tr>");
            for (int i = 1; i <= 9; i++)
            {
                sb.Append("<tr>");
                sb.Append("<td style='border:1px solid #abd;200px;'>" + i * 1 + "</td>");
                sb.Append("<td style='border:1px solid #abd;500px;'>" + i * 2 + "</td>");
                sb.Append("<td colspan='2' style='border:1px solid #abd;300px;'>" + i * 4 + "</td>");
                sb.Append("</tr>");
            }
            sb.Append("</table>");
            sb.Append("<table style='1000px;'>");
            sb.Append("<tr style='background: green'><td align='center' valign='middle' colspan='4'>这是表格标题</td></tr>");
            sb.Append("<tr style='border:1px solid #F3F3F4'><th>t1</th><th>t2</th><th colspan='2'>t3t4</th></tr>");
            for (int i = 1; i <= 9; i++)
            {
                sb.Append("<tr>");
                for (int j = 1; j <= 4; j++)
                {
                    sb.Append("<td style='border:1px solid #abd;'>" + i * j + "</td>");
                }
                sb.Append("</tr>");
            }
            sb.Append("</table>");
            File.WriteAllBytes("abc.xls", Encoding.Default.GetBytes(sb.ToString()));
            Process.Start("abc.xls");
        }