以xls格式导出报告使用php不显示网格线
我有一个报告以xls格式输出。 这个报告是以xls格式成功导出的，但是网格线从来没有出现，即使我已经在ms excel中通过选中视图网格线checkbox来调整一些选项，但网格线仍然不显示任何内容。 我怀疑如果有可能是我的PHP导出代码有问题。 你能帮我一下吗？ 这是我的代码。
xls导出代码
<?php $file="report.xls"; $export ='<center><h1 class="lead">CITY Chamber</h1><img src= "base_url(images/agri_logo.jpg)" width="130px" height="130px"></center> <div id="page-wrapper"> <table class="table table-bordered table-hover table-striped tablesorter"> <tr> <td>First Name: </td> <td>'.$report_rows[0]->fname.'</td> </tr> <tr> <td>Last Name: </td> <td>'. $report_rows[0]->lname.'</td> </tr> <tr> <td>Gender: </td> <td>'.$report_rows[0]->gender.'</td> </tr> <tr> <td>Contact Number: </td> <td>'.$report_rows[0]->contact.'</td> </tr> </table> <table class="table table-bordered table-hover table-striped tablesorter"> <div class="table-responsive"> <table class="table table-bordered table-hover table-striped tablesorter"> <thead> <tr> <td colspan="2"><strong>Key Result Areas (KRA) / Program / Projects / Activities</strong></td> <td><strong>Target</strong></td> <td colspan="2" style="text-align:center;"><center> '.$report_rows[0]->prev_month_year.'</center></td> <td colspan="2" ><center> '.$report_rows[0]->pres_month_year.' </center></td> <td><strong>Total</strong></td> </tr> </thead> <form id="at_report_form" method="post"> <tbody> <tr> <td></td> <td></td> <td></td> <td> '.$dropdown_brgy1[$data_reports['prev_brgy1']].' </td> <td> '.$dropdown_brgy1[$data_reports['prev_brgy2']].' </td> <td> '.$dropdown_brgy1[$data_reports['pres_brgy1']].' </td> <td> '.$dropdown_brgy1[$data_reports['pres_brgy2']].' </td> <td></td> </tr> <tr> <td>1. KRA No. 1: Production Enhancement & Environment </td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td> Protection Agenda (PEEPA)</td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td>1.1 Support to Crop Production Enhancement </td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td>1.1.1 Rice Production Self Sufficiency Program</td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> <tr> <td><span style="margin-left:30px;">a. Provision of certified seeds</span></td> <td>no. of bags</td> <td>per AT</td> <td><center> '.$data_reports['a'].'</center></td> <td> <center>'.$data_reports['b'].'</center></td> <td><center> '.$data_reports['c'].'</center></td> <td> <center>'.$data_reports['d'].'</center></td> <td><center> '.$data_reports['total_1'].'</center></td> </tr> <tr> <td></td> <td>no. of farmers</td> <td></td> <td><center>'.$data_reports['e'].'</center></td> <td><center>'.$data_reports['f'].'</center></td> <td><center>'.$data_reports['g'].'</center></td> <td><center>'.$data_reports['h'].'</center></td> <td><center>'.$data_reports['total_2'].'</center></td> </tr> <tr> <td style="text-align:center;">Rehab Seeds</td> <td>no. of bags</td> <td>per AT</td> <td><center>'.$data_reports['i'].'</center></td> <td><center>'.$data_reports['j'].'</center></td> <td><center>'.$data_reports['k'].'</center></td> <td><center>'.$data_reports['l'].'</center></td> <td><center>'.$data_reports['total_3'].'</center></td> </tr> <tr> <td></td> <td>no. of farmers</td> <td></td> <td><center>'.$data_reports['m'].'</center></td> <td><center>'.$data_reports['n'].'</center></td> <td><center>'.$data_reports['o'].'</center></td> <td><center>'.$data_reports['p'].'</center></td> <td><center>'.$data_reports['total_4'].'</center></td> </tr> <tr> <td><span style="margin-left:30px;">b. Provision of pest control assistance</span></td> <td>no. of kgs (ratoxin)</td> <td>per AT</td> <td><center>'.$data_reports['q'].'</center></td> <td><center>'.$data_reports['r'].'</center></td> <td><center>'.$data_reports['s'].'</center></td> <td><center>'.$data_reports['t'].'</center></td> <td><center>'.$data_reports['total_5'].'</center></td> </tr> </tbody> </form> </table></div></div>'; header("Content-type: application/vnd.ms-excel"); header("Content-Disposition: attachment; filename=$file"); echo $export; ?> 输出（即使我已经检查了网格视图checkbox，网格线也不会显示）：
optput你的HTML使用表标签使用
<table border=1>