php中怎样实现图片的打包下载

<?php class zipfile { var $datasec = array (); var $ctrl_dir = array (); var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00"; var $old_offset = 0; function unix2_dostime($unixtime = 0){ $timearray = ($unixtime == 0) ? getdate () : getdate($unixtime); if ($timearray ['year'] < 1980){ $timearray ['year'] = 1980; $timearray ['mon'] = 1; $timearray ['mday'] = 1; $timearray ['hours'] = 0; $timearray ['minutes'] = 0; $timearray ['seconds'] = 0; } return (($timearray ['year'] - 1980) << 25) | ($timearray ['mon'] << 21) | ($timearray ['mday'] << 16) | ($timearray ['hours'] << 11) | ($timearray ['minutes'] << 5) | ($timearray ['seconds'] >> 1); } function add_file($data, $name, $time = 0){ $name = <?php class zipfile { var $datasec = array ();