Implementieren Sie eine Codeanalyse der Online-Zahlungsfunktion des WeChat-Applets

wx.login({
      success: function(res) {
        if (res.code) {
          //发起网络请求
          wx.request({
            url: 'https://yourwebsit/onLogin',
            method: 'POST',
            data: {
              code: res.code
            },
            success: function(res) {
                var openid = res.data.openid;
            },
            fail: function(err) {
                console.log(err)
            }
          })
        } else {
          console.log('获取用户登录态失败！' + res.errMsg)
        }
      }
    });

var code = req.param("code");
        request({
            url: "https://api.weixin.qq.com/sns/jscode2session?appid="+appid+"&secret="+secret+"&js_code="+code+"&grant_type=authorization_code",
            method: 'GET'
        }, function(err, response, body) {
            if (!err && response.statusCode == 200) {
                res.json(JSON.parse(body));
            }
        });

function jsApiCall()
        {
            WeixinJSBridge.invoke(
                'getBrandWCPayRequest',
                {
                   "appId":"",     //公众号名称，由商户传入     
                   "timeStamp":"",         //时间戳，自1970年以来的秒数     
                   "nonceStr":"", //随机串     
                   "package":"prepay_id=",     
                   "signType":"MD5",         //微信签名方式：     
                   "paySign":"" //微信签名
                },
                function(res){
                    WeixinJSBridge.log(res.err_msg);
                    if( res.err_msg =="get_brand_wcpay_request:ok"){
                        alert("支付成功!");
                    }else{
                        alert("支付失败!");
                    }
                }
            );
        }

              wx.request({
                    url: 'https://yourwebsit/service/getPay', 
                    method: 'POST',
                    data: {
                      bookingNo:bookingNo,  /*订单号*/
                      total_fee:total_fee,   /*订单金额*/
                      openid:openid
                    },
                    header: {
                        'content-type': 'application/json'
                    },
                    success: function(res) {
                        wx.requestPayment({
                          'timeStamp':timeStamp,
                          'nonceStr': nonceStr,
                          'package': 'prepay_id='+res.data.prepay_id,
                          'signType': 'MD5',
                          'paySign': res.data._paySignjs,
                          'success':function(res){
                              console.log(res);
                          },
                          'fail':function(res){
                              console.log('fail:'+JSON.stringify(res));
                          }
                        })
                    },
                    fail: function(err) {
                        console.log(err)
                    }
                })

        var bookingNo = req.param("bookingNo");
        var total_fee = req.param("total_fee");
        var openid = req.param("openid");
        var body = "费用说明";
        var url = "https://api.mch.weixin.qq.com/pay/unifiedorder";
        var formData = "<xml>";
        formData += "<appid>appid</appid>"; //appid
        formData += "<attach>test</attach>";
        formData += "" + body + "";
        formData += "<mch_id>mch_id</mch_id>"; //商户号
        formData += "<nonce_str>nonce_str</nonce_str>";
        formData += "<notify_url>notify_url</notify_url>";
        formData += "<openid>" + openid + "</openid>";
        formData += "<out_trade_no>" + bookingNo + "</out_trade_no>";
        formData += "<spbill_create_ip>spbill_create_ip</spbill_create_ip>";
        formData += "<total_fee>" + total_fee + "</total_fee>";
        formData += "<trade_type>JSAPI</trade_type>";
        formData += "<sign>" + paysignjsapi(appid, attach, body, mch_id, nonce_str, notify_url, openid, bookingNo, spbill_create_ip, total_fee, 'JSAPI') + "</sign>";
        formData += "</xml>";
        request({
            url: url,
            method: 'POST',
            body: formData
        }, function(err, response, body) {
            if(!err && response.statusCode == 200) {
                var prepay_id = getXMLNodeValue('prepay_id', body.toString("utf-8"));
                var tmp = prepay_id.split('[');
                var tmp1 = tmp[2].split(']');
                //签名
                var _paySignjs = paysignjs(appid, mch_id, 'prepay_id=' + tmp1[0], 'MD5',timeStamp);
                var o = {
                    prepay_id: tmp1[0],
                    _paySignjs: _paySignjs
                }
                res.send(o);
            }
        });

function paysignjs(appid, nonceStr, package, signType, timeStamp) {
    var ret = {
        appId: appid,
        nonceStr: nonceStr,
        package: package,
        signType: signType,
        timeStamp: timeStamp
    };
    var string = raw1(ret);
    string = string + '&key='+key;
    console.log(string);
    var crypto = require('crypto');
    return crypto.createHash('md5').update(string, 'utf8').digest('hex');
};

function raw1(args) {
    var keys = Object.keys(args);
    keys = keys.sort()
    var newArgs = {};
    keys.forEach(function(key) {
        newArgs[key] = args[key];
    });

    var string = '';
    for(var k in newArgs) {
        string += '&' + k + '=' + newArgs[k];
    }
    string = string.substr(1);
    return string;
};

function paysignjsapi(appid, attach, body, mch_id, nonce_str, notify_url, openid, out_trade_no, spbill_create_ip, total_fee, trade_type) {
    var ret = {
        appid: appid,
        attach: attach,
        body: body,
        mch_id: mch_id,
        nonce_str: nonce_str,
        notify_url: notify_url,
        openid: openid,
        out_trade_no: out_trade_no,
        spbill_create_ip: spbill_create_ip,
        total_fee: total_fee,
        trade_type: trade_type
    };
    var string = raw(ret);
    string = string + '&key='+key;
    var crypto = require('crypto');
    return crypto.createHash('md5').update(string, 'utf8').digest('hex');
};

function raw(args) {
    var keys = Object.keys(args);
    keys = keys.sort()
    var newArgs = {};
    keys.forEach(function(key) {
        newArgs[key.toLowerCase()] = args[key];
    });

    var string = '';
    for(var k in newArgs) {
        string += '&' + k + '=' + newArgs[k];
    }
    string = string.substr(1);
    return string;
};

function getXMLNodeValue(node_name, xml) {
    var tmp = xml.split("");
    var _tmp = tmp[1].split("" + node_name + ">");
    return _tmp[0];
}