解析PHP实现下载文件的两种方法

方法一：
代码如下:
 header('Content-Description: File Transfer');
 header('Content-Type: application/octet-stream');
 header('Content-Disposition: attachment; filename='.basename($filepath));
 header('Content-Transfer-Encoding: binary');
 header('Expires: 0′);
 header('Cache-Control: must-revalidate, post-check=0, pre-check=0′);
 header('Pragma: public');
 header('Content-Length: ' . filesize($filepath));
 readfile($file_path);

方法二：
代码如下:
 $fileinfo = pathinfo($filename);
 header('Content-type: application/x-'.$fileinfo['extension']);
 header('Content-Disposition: attachment; filename='.$fileinfo['basename']);
 header('Content-Length: '.filesize($filename));
 readfile($thefile);
 exit();