只提供微信小程序端代碼：

 1 var app = getApp();
 2 Page({
 3   data: {},
 4   onLoad: function (options) {
 5     // 頁面初始化 options為頁面跳轉所帶來的參數
 6     var that = this
 7     //登陸獲取code
 8     wx.login({
 9       success: function (res) {
10         console.log(res.code)
11         //獲取openid
12         that.getOpenId(res.code)
 
13       }
14     });
15   },
16   getOpenId: function (code) {
17     var that = this;
18     wx.request({
19       url: "https://api.weixin.qq.com/sns/jscode2session?appid=小程序appid&secret=小程序應用密鑰&js_code=" + code + "&grant_type=authorization_code",
20       data: {},
21       method: ‘GET‘,
 
22       success: function (res) {
23         that.generateOrder(res.data.openid)
24       },
25       fail: function () {
26         // fail
27       },
28       complete: function () {
29         // complete
30       }
31     })
32   },
33   /**生成商戶訂單 */
34   generateOrder: function (openid) {
35     var
 
 that = this
36     //統一支付
37     wx.request({
38       url: ‘後臺路徑‘,
39       method: ‘GET‘,
40       data: {
41         gfee: ‘商品價錢‘,
42         gname: ‘商品名稱‘,
43         openId:openid
44         （商品價錢和商品名稱根據自身需要是否傳值,openid為必傳）
45       },
46       success: function (res) {
47         var pay = res.data
48         //發起支付
49         var timeStamp = pay[0].timeStamp;
50         var packages = pay[0].package;
51         var paySign = pay[0].paySign;
52         var nonceStr = pay[0].nonceStr;
53         var param = { "timeStamp": timeStamp, "package": packages, "paySign": paySign, "signType": "MD5", "nonceStr": nonceStr };
54         that.pay(param)
55       },
56     })
57   },
58  
59   /* 支付  */
60   pay: function (param) {
61     console.log("支付")
62     console.log(param)
63     wx.requestPayment({
64       timeStamp: param.timeStamp,
65       nonceStr: param.nonceStr,
66       package: param.package,
67       signType: param.signType,
68       paySign: param.paySign,
69       success: function (res) {
70         // success
71         wx.navigateBack({
72           delta: 1, // 回退前 delta(默認為1) 頁面
73           success: function (res) {
74             wx.showToast({
75               title: ‘支付成功‘,
76               icon: ‘success‘,
77               duration: 2000
78             })
79           },
80           fail: function () {
81             // fail
82  
83           },
84           complete: function () {
85             // complete
86           }
87         })
88       },
89       fail: function (res) {
90         // fail
91       },
92       complete: function () {
93         // complete
94       }
95     })
96   }
97 })

微信小程序 支付功能（前端）的實現