uniapp+nodejs微信支付小程序版

前端代码

weChatPay() {
	uni.request({
		url: 'http://www.xxxx.com/wechat/wxmporder',//调用下单接口
		data: {id},
		dataType: 'json',
		method: 'POST'
	}).then(response => {
		uni.requestPayment({
			provider: 'wxpay',
			timeStamp: pay.timeStamp + '',//注意这里要字符串，不能是数字
			nonceStr: pay.nonceStr,
			package: pay.package,
			signType: pay.signType,
			paySign: pay.paySign,
			success: function(res) {//支付成功回调
				uni.showModal({
					title: '提示',
					content: '支付成功',
					showCancel: false,
					success: res => {
						
					},
				});
				console.log('success:' + JSON.stringify(res));
			},
			fail: function(err) {
				console.log('fail:' + JSON.stringify(err));
			}
		});
	})
}

后台代码

router.all('/wxmporder', async function (req, res, next) {
  
  const appid = '小程序appid'
  //小程序登录用户openId
  const openid = '';
  const total_fee = 1;//整数，单位分
  const body = '商品1'
  const moment = require('moment')
  const out_trade_no = moment(new Date()).format('YYYYMMDDHHmmss')
  const notify_url = 'http://www.xxxx.com/wechat/wechatNotify'//异步通知地址
  const prepay_id = await Unifiedorder(appid, openid, body, total_fee, out_trade_no, notify_url, 'JSAPI')//预支付交易会话标识
  const stringUtils = require('../utils/stringUtils')
  const responseData = {
    appId: appid,
    timeStamp: new Date().getTime(),
    nonceStr: stringUtils.randomString(20),
    package: 'prepay_id=' + prepay_id,
    signType: 'MD5',
  }
  const CryptoJS = require('crypto-js');
  const resultSignStr = getSignStr(responseData)
  responseData.paySign = CryptoJS.MD5(resultSignStr + '&key=' + mch_key).toString().toUpperCase()
  res.send({ pay: responseData })
})

拼接签名字符串方法

function getSignStr(map) {
  let sortKeys = Object.keys(map).sort((a, b) => {
    let index = 0;
    while (true) {
      let ai = index >= a.length ? 0 : a[index].charCodeAt()
      let bi = index >= b.length ? 0 : b[index].charCodeAt()
      let sub = ai - bi;
      if (sub != 0 || (index >= a.length && index >= b.length)) {
        return sub;
      }
      index++;
    }
  })
  let arr = [];
  for (let i in sortKeys) {
    let key = sortKeys[i];
    let val = map[key];
    if (val == null || val == '') {
      continue
    }
    arr.push(key + '=' + val)
  }
  return arr.join('&')
}

统一下单方法

//微信统一下单
function Unifiedorder(appid, openid, body, total_fee, orderNo, notify_url, trade_type) {
  return new Promise(async (resolve, reject) => {
    try {
      const out_trade_no = orderNo
      const spbill_create_ip = '192.168.3.20';
      const stringUtils = require('../utils/stringUtils')
      const nonce_str = stringUtils.randomString(20)
      let map = {
        appid, mch_id, nonce_str, body, out_trade_no, total_fee, spbill_create_ip, notify_url, trade_type, openid
      }
      const CryptoJS = require('crypto-js');
      const signStr = getSignStr(map);
      console.log('签名字符串：' + signStr)
      //MD5签名转大写
      const sign = CryptoJS.MD5(signStr + '&key=' + mch_key).toString().toUpperCase()
      console.log(sign)

      let url = 'https://api.mch.weixin.qq.com/pay/unifiedorder'
      map.sign = sign

      //组装xml数据
      var formData = "";
      formData += "" + appid + "";  //appid
      formData += " + body + "]]>";
      formData += "" + mch_id + "";  //商户号
      formData += "" + nonce_str + ""; //随机字符串，不长于32位。
      formData += "" + notify_url + "";
      formData += "" + out_trade_no + "";
      formData += "" + spbill_create_ip + "";
      formData += "" + total_fee + "";
      formData += "" + trade_type + "";
      formData += "" + openid + "";
      formData += "" + sign + "";
      formData += "";
      console.log('统一下单参数:' + formData)
      const http = require('../utils/httpUtils')
      let result = await http.post(url, formData)
      console.log('统一下单结果:' + result)
      var xmlreader = require("xmlreader");
      xmlreader.read(result, function (errors, response) {
        if (!errors) {
          const return_code = response.xml.return_code.text()
          if (return_code == 'SUCCESS') {
            const prepay_id = response.xml.prepay_id.text()//预支付交易会话标识
            resolve(prepay_id)
          }
        } else {
          reject(errors)
        }
      });
    } catch (error) {
      reject(error)
    }
  })
}