解决苹果手机下载文件文件名称乱码的问题

问题说明：今天再做附件下载时，因为附件名称为中文，在苹果手机safari浏览器下载文件中文名称直接乱码，如图：

解决方法：
php代码:

public fuction downloadFile($fileurl, $filename, $charset = 'UTF-8'){
   if (preg_match("/MSIE/", $_SERVER["HTTP_USER_AGENT"])) {
      $filename = urlencode($filename);
      $filename = str_replace("+", "%20", $filename);// 替换空格
      $attachment = "attachment; filename=\"{$filename}"; charset={$charset}"; 
   } else if (preg_match("/Firefox/", $_SERVER["HTTP_USER_AGENT"])) {
      $attachment = 'attachment; filename*=utf-8\'\'' . $filename; 
   } else if (preg_match("/Safari/", $_SERVER["HTTP_USER_AGENT"])) {
      $filename = rawurlencode($filename); // 注意：rawurlencode与urlencode的区别
      $attachment = 'attachment; filename*=utf-8\'\'' . $filename;
   } else {
      $filename = rawurlencode($filename);
      $attachment = "attachment; filename=\"{$filename}"; charset={$charset}";
   }
   header('Pragma: public');
   header("Content-Transfer-Encoding: Binary");
   header('Content-Type: application/octet-stream');
   header("Content-disposition:".$attachment."");
   readfile($fileurl);  
}