为什么文件下载损坏？

Question

我要下载所有格式（图像，视频，音频，PDF，文本和所有Microsoft Office文档类型）而不会出现错误，我是否应该指定MIME类型？

header('Pragma: public');   
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Cache-Control: private',false);
header('Content-Type: application/force-download');
header('Content-Disposition: attachment; filename='.$fileName);
header('Content-Transfer-Encoding: binary');
header('Content-Length: '.filesize($filePath));
header('Connection: close');
readfile($filePath);    
exit () ;