php中强制下载文件的代码

php中强制下载文件的代码（解决了IE下中文文件名乱码问题）

浏览器提交excel格式的数据和文件名到服务器上，将请求转化为可下载的excel文件，并要求浏览器弹出文件下载提示窗口

中间遇到一个问题是提交的中文文件名直接放到header里在IE下会变成乱码，解决方法是将文件名先urlencode一下再放入header，如下。 

<?php
$file_name = urlencode($_REQUEST['filename']);
header("Pragma: public"); header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header('Content-Type: application/vnd.ms-excel; charset=utf-8');
header("Content-Transfer-Encoding: binary");
header('Content-Disposition: attachment; filename='.$file_name);
echo stripslashes($_REQUEST['content']);
?>

解决PHP Header下载文件在IE文件名中文乱码有两种常见的，一种是是把页面编码改成utf8，另一种是对中文url进入urlencode编码就可以解决了。 
解决方案一(我的页面是utf-8编码)： 

$filename = "中文.txt";
$ua = $_SERVER["HTTP_USER_AGENT"];
$encoded_filename = urlencode($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 . '"');
}

解决方法二 
将文件名先urlencode一下再放入header，如下。 

<?php
$file_name = urlencode($_REQUEST['filename']);
header("Pragma: public"); header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header('Content-Type: application/vnd.ms-excel; charset=utf-8');
header("Content-Transfer-Encoding: binary");
header('Content-Disposition: attachment; filename='.$file_name);
echo stripslashes($_REQUEST['content']);
?>