PHP 浏览器下载图片

  public function download(){
        $param = input('param.');
      / $id = $param['id'];
        $path = Db('slide')->where(['id'=>$id])->value('image');    //图片路径
        if(!file_exists('.'.$path)){
            die(handleResult(0, '文件不存在或已经删除'));
        };
        $request = Request::instance();
        $domain = $request->domain();   //当前域名
        $file = $domain.$path;    //图片完整路径
        $fileTmp = pathinfo($file);
        $fileExt = $fileTmp['extension'];    //图片后缀名
        $filename = Md5($fileTmp['filename']);   //图片名称，可以任务设置图片名称
        $saveFileName = ($filename.'.'.$fileExt);
        $fp=fopen($file,"r");
        //下载文件需要用到的头
        Header("Content-type: application/octet-stream");
        Header("Accept-Ranges: bytes");
        Header("Content-Disposition: attachment; filename=".$saveFileName);
        $buffer=1024;
        $file_count=0;
        //向浏览器返回数据
        while(!feof($fp)){
            $file_con=fread($fp,$buffer);
            $file_count+=$buffer;
            echo $file_con;
        }
        fclose($fp);
        exit;

    }