ajax下载文件的方法 php下载图片的方法详解编程语言

 public function xiazai() 
    { 
        $file_path = __DIR__ . '/../../../Public/qitan.pdf'; 
 
 
        $fp        = fopen($file_path, "r"); 
        $file_size = filesize($file_path); 
//下载文件需要用到的头 
        Header("Content-type: application/octet-stream"); 
        Header("Accept-Ranges: bytes"); 
        Header("Accept-Length:" . $file_size); 
        Header("Content-Length:" . $file_size); 
        Header("Content-Disposition: attachment; filename=qitan.pdf"); 
 
        $buffer     = 1024; 
        $file_count = 0; 
//向浏览器返回数据 
        while (!feof($fp) && $file_count < $file_size) { 
            $file_con = fread($fp, $buffer); 
            $file_count += $buffer; 
            echo $file_con; 
        } 
        fclose($fp); 
    }