回答

<?php

//调用get_qrcode方法，获取二维码图片

$base64_img = get_qrcode($id);



//调用base64_save方法，将图片保存到指定位置，并获取图片新名称

$new_name = base64_save($base64_img, './Uploads/qrcode/');





//生成二维码

function get_qrcode($id) {

    $APPID = "xxxx";

    $APPSECRET = "xxxxxxxxx";



    //获取access_token

    $access_token = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$APPID&secret=$APPSECRET";

    

    //这里可以对这个access_token做2小时过期缓存



    //缓存access_token

    session_start();

    $_SESSION['access_token'] = "";

    $_SESSION['expires_in'] = 0;



    $ACCESS_TOKEN = "";

    if (!isset($_SESSION['access_token']) || (isset($_SESSION['expires_in']) && time() > $_SESSION['expires_in'])) {

        $json = httpRequest($access_token);

        $json = json_decode($json, true);



        $_SESSION['access_token'] = $json['access_token'];

        $_SESSION['expires_in'] = time()+7200;

        $ACCESS_TOKEN = $json["access_token"];

    } else {

        $ACCESS_TOKEN = $_SESSION["access_token"];

    }



    //构建请求二维码参数

    //path是扫描二维码跳转的小程序路径，可以带参数?id=xxx

    //width是二维码宽度

    $qcode = "https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode?access_token=$ACCESS_TOKEN";

    $param = json_encode(array("path" => "pages/index/index?tuiguangid=$id", "width" => 150));



    //POST参数

    $result = httpRequest($qcode, $param, "POST");



    //生成二维码

    // file_put_contents("qrcode.png", $result);

    $base64_image = "data:image/jpeg;base64,".base64_encode($result);



    return $base64_image; //返回base64图片数据

}



//把请求发送到微信服务器换取二维码

function httpRequest($url, $data = '', $method = 'GET') {

    $curl = curl_init();

    curl_setopt($curl, CURLOPT_URL, $url);

    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);

    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);

    curl_setopt($curl, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);

    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);

    curl_setopt($curl, CURLOPT_AUTOREFERER, 1);

    if ($method == 'POST') {

        curl_setopt($curl, CURLOPT_POST, 1);

        if ($data != '') {

            curl_setopt($curl, CURLOPT_POSTFIELDS, $data);

        }

    }



    curl_setopt($curl, CURLOPT_TIMEOUT, 30);

    curl_setopt($curl, CURLOPT_HEADER, 0);

    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

    $result = curl_exec($curl);

    curl_close($curl);

    return $result;

}



/*

 * 保存base64格式图片到指定文件夹中

 * $base64_img 图片数据

 * $path 要保存到的图片地址

 */

function base64_save($base64_img, $path) {

    $img_base = str_replace('data:image/jpeg;base64,', '', $base64_img);

    $img_name = time().rand(1000, 9999).'.jpg'; //图片新名称

    $img_path = $path.$img_name;

    file_put_contents($img_path, base64_decode($img_base));



    return $img_name; //返回新名称

}

那么小程序端获取这个tuiguangid的参数代码

onLoad: function (options) {
    if (options.tuiguangid!= undefined) {
      console.log(options.tuiguangid)
    }
}

当然还可以使用scene传值，这里采用的path传参。