php 文件下载 出现下载文件内容乱码损坏的解决办法

public function download(){ $upload=M('upload'); $data=$upload->find($_GET['id']); if(empty($data)){ header('HTTP/1.0 404 Not Found'); header('Location: .'); }else{ $path='./public/Uploads/'.$data['savename']; header("Content-Type:".$data['type']); header('Content-Disposition: attachment; filename="'.$data['name'].'"'); header('Content-Length:'.$data['size']); ob_clean(); flush(); readfile($path); }}

ob_clean();flush();