PHP: WeChat Mini Program WeChat Payment Server Integration Example Detailed Explanation

WeChat Mini Program WeChat Payment Server Set

Theoretically, all the work of integrating WeChat Payment can be completed on the Mini Program, because the Mini Program js has the ability to access the network, but for the sake of security, sensitive keys are not exposed , and you can use the official ready-made php demo to save more effort, so you complete the signature and initiate the request on the server side, and the applet only connects to a wx.requestPayment (OBJECT) interface.

The overall integration process is similar to JSAPI and APP. First place an order in a unified manner, and then use the returned results to request payment.

A total of three steps:

1. The applet exchanges the code returned by wx.login for openid 2. The server places an order to WeChat 3. The applet initiates payment

Prepare these things in advance:

APPID = 'wx426b3015555a46be';
MCHID = '1900009851';
KEY = '8934e7d15453e97507ef794cf7b0519d';
APPSECRET = '7813490da6f1265e4901ffb80afaa36f';

PHP SDK, the download link is at the end of the article

The 1st and 4th items are obtained when applying for the mini program , the 2nd and 3rd items were obtained when applying to open WeChat payment. Note that the 3rd and 4th items look similar, but they are actually two things. Confusing the two will cause the signature to fail.

Place an order on WeChat and get the prepay_id

1. Create a Controller and import the WxPay.Api.php class

<?php
require_once __DIR__ . &#39;/BaseController.php&#39;;
require_once __DIR__ . &#39;/../third_party/wxpay/WxPay.Api.php&#39;;
 
class WXPay extends BaseController {
  function index() {
  }
}

After that, you can pass index.php/wxpay to make access requests

2. Modify the configuration file WxPay.Config.php

and change it to apply for the corresponding key yourself

3. Implement the index method

function index() {
//     初始化值对象
    $input = new WxPayUnifiedOrder();
//     文档提及的参数规范：商家名称-销售商品类目
    $input->SetBody("灵动商城-手机");
//     订单号应该是由小程序端传给服务端的，在用户下单时即生成，demo中取值是一个生成的时间戳
    $input->SetOut_trade_no('123123123');
//     费用应该是由小程序端传给服务端的，在用户下单时告知服务端应付金额，demo中取值是1，即1分钱
    $input->SetTotal_fee("1");
    $input->SetNotify_url("http://paysdk.weixin.qq.com/example/notify.php");
    $input->SetTrade_type("JSAPI");
//     由小程序端传给服务端
    $input->SetOpenid($this->input->post('openId'));
//     向微信统一下单，并返回order，它是一个array数组
    $order = WxPayApi::unifiedOrder($input);
//     json化返回给小程序端
    header("Content-Type: application/json");
    echo json_encode($order);
  }

Note 1: The nonce_str mentioned in the document is not not submitted, but filled in by the sdk for us

The source is line 55 of WxPay.Api.php

$inputObj->SetNonce_str(self::getNonceStr());//随机字符串

Note 2: sign has also been kindly given to setSign. The source is in line 111 of WxPay.Data.php, MakeSign()

/**
  * 生成签名
  * @return 签名，本函数不覆盖sign成员变量，如要设置签名需要调用SetSign方法赋值
  */
 public function MakeSign()
 {
   //签名步骤一：按字典序排序参数
   ksort($this->values);
   $string = $this->ToUrlParams();
   //签名步骤二：在string后加入KEY
   $string = $string . "&key=".WxPayConfig::KEY;
   //签名步骤三：MD5加密
   $string = md5($string);
   //签名步骤四：所有字符转为大写
   $result = strtoupper($string);
   return $result;
 }

4. Call the login interface in the mini program to get the openid

Make a login request to WeChat, get the code, and then submit the code in exchange for the openId

wx.login({
     success: function(res) {
      if (res.code) {
       //发起网络请求
       wx.request({
        url: 'https://api.weixin.qq.com/sns/jscode2session?appid=wx9114b997bd86f***&secret=d27551c7803cf16015e536b192******&js_code='+res.code+'&grant_type=authorization_code',
        data: {
         code: res.code
        },
        success: function (response) {
          console.log(response);
        }
       })
      } else {
       console.log('获取用户登录态失败！' + res.errMsg)
      }
     }
    });

From the console Seeing that the openid has been successfully obtained, the only thing left is to pass it to the server. The server is waiting for $this->input->post('openId').

5. The mini program initiates a request to https://lendoo.leanapp.cn/index.php/WXPay and makes a unified order

//统一下单接口对接
      wx.request({
        url: 'https://lendoo.leanapp.cn/index.php/WXPay',
        data: {
          openId: openId
        },
        success: function (response) {
          console.log(response);
 
        },
            header: {
        'content-type': 'application/x-www-form-urlencoded'
    },
      });

and gets the following results

{
 "appid": "wx9114b997bd86f8ed",
 "mch_id": "1414142302",
 "nonce_str": "eEICgYFuGqxFRK6f",
 "prepay_id": "wx201701022235141fc713b8f80137935406",
 "result_code": "SUCCESS",
 "return_code": "SUCCESS",
 "return_msg": "OK",
 "sign": "63E60C8CD90394FB50E612D085F5362C",
 "trade_type": "JSAPI"
}

The premise is that https://lendoo.leanapp.cn is already in the whitelist:

6. Call up the payment API on the mini program

// 发起支付
var appId = response.data.appid;
var timeStamp = (Date.parse(new Date()) / 1000).toString();
var pkg = 'prepay_id=' + response.data.prepay_id;
var nonceStr = response.data.nonce_str;
var paySign = md5.hex_md5('appId='+appId+'&nonceStr='+nonceStr+'&package='+pkg+'&signType=MD5&timeStamp='+timeStamp+"&key=d27551c7803cf16***e536b192d5d03b").toUpperCase();
console.log(paySign);
console.log(appId);
wx.requestPayment({
  'timeStamp': timeStamp,
  'nonceStr': nonceStr,
  'package': pkg,
  'signType': 'MD5',
  'paySign': paySign,
  'success':function(res){
    console.log('success');
    console.log(res);
  }
});

When testing the simulator, a QR code will pop up for scanning

The result is an error:

errMsg:"requestPayment:fail"
err_code:2
err_desc:"支付验证签名失败"

key needs to be added to the signature! ! ! 'appId='+appId+'&nonceStr='+nonceStr+'&package='+pkg+'&signType=MD5&timeStamp='+timeStamp+"&key=d27551c7803cf16*e536b192d5d03b"This is complete.

But there is no mention of key in the document

Screenshot of successful payment

More PHP: WeChat Please pay attention to the PHP Chinese website for related articles on detailed explanations of WeChat payment server integration examples of mini programs and source code downloads!