1 function download($file){ 2     //文件根路径 3     $filename=$_SERVER[‘DOCUMENT_ROOT‘].__ROOT__.‘/‘.$file; 4     //下载文件 5     if(!file_exists($filename)){ 6         $this->error("找不到文件"); 7         exit; 8     }else{ 9         header("Content-Type:text/html;charset=utf-8");10         header("Content-type:application/force-download");11         header("Content-Type:application/octet-stream");13         header("Accept-Ranges:bytes");14         header("Content-Length:".filesize($filename));//指定下载文件的大小15         header(‘Content-Disposition:attachment;filename="‘.$file.‘"‘);16         //必要时清除缓存17         ob_clean();18         flush();19         readfile($filename);20         exit();21     }22 }