book_admin/application/main/helper/FileHelper.php

<?php
/**
 * Created by PhpStorm.
 * User: Bear
 * Date: 2019/2/21
 * Time: 下午2:05
 */

namespace app\main\helper;


class FileHelper
{
    public static function downloadCsv($title, $csv_body)
    {
        $fileName = $title . '.csv';
        // 头部标题
        $content = '';
        foreach ($csv_body as $k => $v) {
            $content .= implode(',', $v) . PHP_EOL;
        }
        $csvData = iconv('UTF-8','GB2312//IGNORE', $content);
        header("Content-type:text/csv;");
        header("Content-Disposition:attachment;filename=" . $fileName);
        header('Cache-Control:must-revalidate,post-check=0,pre-check=0');
        header('Expires:0');
        header('Pragma:public');
        echo $csvData;exit;
    }
}