跨浏览器PHP下载文件名中的中文乱码问题解决方法

<?php

$ua = $_SERVER["HTTP_USER_AGENT"];

$filename = "中文 文件名.txt";

$encoded_filename = urlencode($filename);

$encoded_filename = str_replace("+", "%20", $encoded_filename);

header('Content-Type: application/octet-stream');

if (preg_match("/MSIE/", $ua)) {

    header('Content-Disposition: attachment; filename="' . $encoded_filename . '"');

} else if (preg_match("/Firefox/", $ua)) {

    header('Content-Disposition: attachment; filename*="utf8\'\'' . $filename . '"');

} else {

    header('Content-Disposition: attachment; filename="' . $filename . '"');

}

print 'ABC';

?>