微信小程序 支付功能（前端）的实现

var app = getApp();
Page({
data: {},onLoad: function (options) {
// 页面初始化 options为页面跳转所带来的参数
var that = this
//登陆获取code
wx.login({
success: function (res) {
console.log(res.code)
//获取openid
that.getOpenId(res.code)
}
});
},getOpenId: function (code) {
var that = this;
wx.request({
url: "https://api.weixin.qq.com/sns/jscode2session?appid=小程序appid&secret=小程序应用密钥&js_code=" + code + "&grant_type=authorization_code",data: {},method: 'GET',success: function (res) {
that.generateOrder(res.data.openid)
},fail: function () {
// fail
},complete: function () {
// complete
}
})
},/*生成商户订单 /
generateOrder: function (openid) {
var that = this
//统一支付
wx.request({
url: '后台路径',data: {
gfee: '商品价钱',gname: '商品名称',openId:openid
（商品价钱和商品名称根据自身需要是否传值,openid为必传）
},success: function (res) {
var pay = res.data
//发起支付
var timeStamp = pay[0].timeStamp;
var packages = pay[0].package;
var paySign = pay[0].paySign;
var nonceStr = pay[0].nonceStr;
var param = { "timeStamp": timeStamp,"package": packages,"paySign": paySign,"signType": "MD5","nonceStr": nonceStr };
that.pay(param)
},})
},/ 支付 /
pay: function (param) {
console.log("支付")
console.log(param)
wx.requestPayment({
timeStamp: param.timeStamp,nonceStr: param.nonceStr,package: param.package,signType: param.signType,paySign: param.paySign,success: function (res) {
// success
wx.navigateBack({
delta: 1,// 回退前 delta(默认为1) 页面
success: function (res) {
wx.showToast({
title: '支付成功',icon: 'success',duration: 2000
})
},fail: function () {
// fail

      },complete: function () {
        // complete
      }
    })
  },fail: function (res) {
    // fail
  },complete: function () {
    // complete
  }
})

}
})