composer 下载第三方插件库

下载生成二维码的类

composer require bacon/bacon-qr-code

    $renderer = new \BaconQrCode\Renderer\Image\Png();
    $renderer->setHeight(256);
    $renderer->setWidth(256);

    $writer = new \BaconQrCode\Writer($renderer);
    //输出到浏览器
   header('content-type: image/png');
   echo $writer->writeString('Hello World!');

微信支付

https://github.com/pfinal/wechat/blob/master/demo/wxpay.php

导出excel

composer require pfinal/excel