WordPress的主题PHP到PDF转换错误

我使用WordPress作为CMS。所以有一部分我试图从php生成pdf文件。我正在使用phpToPDF生成pdf文件。我在wordpress的自定义模板页面中这样做, 但遇到此错误：

Warning: Cannot modify header information - headers already sent by (output 
started at /Applications/MAMP/htdocs/Wordpress/wp-includes/general-
template.php:2942) in /Applications/MAMP/htdocs/Suburban/wp-
content/themes/custom theme/phpToPDF.php on line 56

试图从核心php生成pdf, 并且可以正常工作…但是我的wordpress网站需要它。

这是代码

<?php 
/* Template Name:test */
wp_head(); 
require("phpToPDF.php");

  $my_html="<div style=\"display:block;\">
  <div style=\"float:left; width:33%; text-align:left;\">
         Left Header Text
  </div>
  <div style=\"float:left; width:33%; text-align:center;\">
         Center Header Text
  </div>
  <div style=\"float:left; width:33%; text-align:right;\">
       Right Header Text
   </div>
   <br style=\"clear:left;\"/>
</div>";

   $pdf_options = array(
    "source_type" => 'php', "source" => $my_html, "action" => 'view', "save_directory" => '', "file_name" => 'pdf_test.pdf');
   phptopdf($pdf_options);

  // echo ("<a href='pdf_invoice.pdf'>Download Your PDF</a>");  
 wp_footer()
  ?>

#1

删除wp_head();和wp_footer()修复了此错误