//index.js
Page({
  data: {

  },
  //点击支付按钮进行支付
  payclick: function () {
    var t = this;
    wx.login({
      //获取code换取openID
      success: function (res) {
        //code = res.code //返回code
        console.log("获取code");
        console.log(res.code);
        var opid = t.getOpenId(res.code);
      }
    })
  },
  //获取openID
  getOpenId: function (code) {
    var that = this;
    wx.request({
      url: "https://api.weixin.qq.com/sns/jscode2session?appid=你的appid&secret=AppSecret(小程序密钥)&js_code=" + code + "&grant_type=authorization_code",
      data: {},
      method: ‘GET‘,
      success: function (res) {
        console.log("获取openid")
        console.log(res)
        that.setData({
          openid: res.data.openid,
          session_key: res.data.session_key
        })
        that.generateOrder(res.data.openid)
      },
      fail: function () {
        // fail
      },
      complete: function () {
        // complete
      }
    })
  },
  //生成商户订单
  generateOrder: function (openid) {
    var that = this
    wx.request({
      url: ‘http://localhost:25492/wx/getda‘,//后台请求地址
      method: ‘GET‘,
      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) {
        console.log("后台获取数据成功");
        console.log(res);
        var param = { "timeStamp": res.data.timeStamp, "package": res.data.package, "paySign": res.data.paySign, "signType": "MD5", "nonceStr": res.data.nonceStr };
         //发起支付
        that.pay(param);
      },
      fail: function (res) {
        console.log("向后台发送数据失败")
      }
    })
  },
  //支付
  pay: function (param) {
    var that = this;
    console.log("发起支付")
    console.log(param)
    wx.requestPayment({
      timeStamp: param.timeStamp,
      nonceStr: param.nonceStr,
      package: param.package,
      signType: param.signType,
      paySign: param.paySign,
      success: function (res) {
        console.log("success");
        console.log(res);
      },
      fail: function (res) {
        console.log("fail")
        console.log(res);
      },
      complete: function (res) {
        console.log("complete");
        console.log(res)
      }
    })
  }
})

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Mvc;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Xml;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
namespace Mvc_vue.Controllers
{
    public class wxController : Controller
    {
        //
        // GET: /wx/

        public ActionResult Index()
        {
            return View();
        }
        //所需值
        public static string _appid = "wxd930ea5d5a258f4f";
        public static string _mch_id = "10000100";
        public static string _key = "192006250b4c09247ec02edce69f6a2d";

        //模拟wx统一下单 openid(前台获取)
        public string getda(string openid)
        {
            return Getprepay_id(_appid, "shanghaifendian", "monixiaofei", _mch_id, GetRandomString(30), "http://www.weixin.qq.com/wxpay/pay.php", openid, getRandomTime(), 1);

        }

        

        //微信统一下单获取prepay_id & 再次签名返回数据
        private static string Getprepay_id(string appid, string attach, string body, string mch_id, string nonce_str, string notify_url, string openid, string bookingNo, int total_fee)
        {
            var url = "https://api.mch.weixin.qq.com/pay/unifiedorder";//微信统一下单请求地址
            string strA = "appid=" + appid + "&attach=" + attach + "&body=" + body + "&mch_id=" + mch_id + "&nonce_str=" + nonce_str + "&notify_url=" + notify_url + "&openid=" + openid + "&out_trade_no=" + bookingNo + "&spbill_create_ip=61.50.221.43&total_fee=" + total_fee + "&trade_type=JSAPI";
            string strk = strA + "&key="+_key;  //key为商户平台设置的密钥key(假)
            string strMD5 = MD5(strk).ToUpper();//MD5签名

            //string strHash=HmacSHA256("sha256",strmd5).ToUpper();   //签名方式只需一种(MD5 或 HmacSHA256     【支付文档需仔细看】)

            //签名
            var formData = "<xml>";
            formData += "<appid>" + appid + "</appid>";//appid  
            formData += "<attach>" + attach + "</attach>"; //附加数据(描述)
            formData += "<body>" + body + "</body>";//商品描述
            formData += "<mch_id>" + mch_id + "</mch_id>";//商户号  
            formData += "<nonce_str>" + nonce_str + "</nonce_str>";//随机字符串，不长于32位。  
            formData += "<notify_url>" + notify_url + "</notify_url>";//通知地址
            formData += "<openid>" + openid + "</openid>";//openid
            formData += "<out_trade_no>" + bookingNo + "</out_trade_no>";//商户订单号    --待
            formData += "<spbill_create_ip>61.50.221.43</spbill_create_ip>";//终端IP  --用户ip
            formData += "<total_fee>" + total_fee + "</total_fee>";//支付金额单位为（分）
            formData += "<trade_type>JSAPI</trade_type>";//交易类型(JSAPI--公众号支付)
            formData += "<sign>" + strMD5 + "</sign>"; //签名
            formData += "</xml>";



            //请求数据
            var getdata = sendPost(url, formData);

            //获取xml数据
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(getdata);
            //xml格式转json
            string json = Newtonsoft.Json.JsonConvert.SerializeXmlNode(doc);



            JObject jo = (JObject)JsonConvert.DeserializeObject(json);
            string prepay_id = jo["xml"]["prepay_id"]["#cdata-section"].ToString();

            //时间戳
            string _time = getTime().ToString();

            //再次签名返回数据至小程序
            string strB = "appId=" + appid + "&nonceStr=" + nonce_str + "&package=prepay_id=" + prepay_id + "&signType=MD5&timeStamp=" + _time + "&key="_key;

            //wx自己写的一个类
            wx w = new wx();
            w.timeStamp = _time;
            w.nonceStr = nonce_str;
            w.package = "prepay_id=" + prepay_id;
            w.paySign = MD5(strB).ToUpper(); ;
            w.signType = "MD5";

            //向小程序返回json数据
             return JsonConvert.SerializeObject(w);
        }

        /// <summary>
        /// 生成随机串    
        /// </summary>
        /// <param name="length">字符串长度</param>
        /// <returns></returns>
        private static string GetRandomString(int length)
        {
            const string key = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789";
            if (length < 1)
                return string.Empty;

            Random rnd = new Random();
            byte[] buffer = new byte[8];

            ulong bit = 31;
            ulong result = 0;
            int index = 0;
            StringBuilder sb = new StringBuilder((length / 5 + 1) * 5);

            while (sb.Length < length)
            {
                rnd.NextBytes(buffer);

                buffer[5] = buffer[6] = buffer[7] = 0x00;
                result = BitConverter.ToUInt64(buffer, 0);

                while (result > 0 && sb.Length < length)
                {
                    index = (int)(bit & result);
                    sb.Append(key[index]);
                    result = result >> 5;
                }
            }
            return sb.ToString();
        }

        /// <summary>
        /// 获取时间戳
        /// </summary>
        /// <returns></returns>
        private static long getTime()
        {
            TimeSpan cha = (DateTime.Now - TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1)));
            long t = (long)cha.TotalSeconds;
            return t;
        }


        /// <summary>
        /// MD5签名方法  
        /// </summary>  
        /// <param name="inputText">加密参数</param>  
        /// <returns></returns>  
        private static string MD5(string inputText)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] fromData = System.Text.Encoding.UTF8.GetBytes(inputText);
            byte[] targetData = md5.ComputeHash(fromData);
            string byte2String = null;

            for (int i = 0; i < targetData.Length; i++)
            {
                byte2String += targetData[i].ToString("x2");
            }

            return byte2String;
        }
        /// <summary>
        /// HMAC-SHA256签名方式
        /// </summary>
        /// <param name="message"></param>
        /// <param name="secret"></param>
        /// <returns></returns>
        private static string HmacSHA256(string message, string secret)
        {
            secret = secret ?? "";
            var encoding = new System.Text.UTF8Encoding();
            byte[] keyByte = encoding.GetBytes(secret);
            byte[] messageBytes = encoding.GetBytes(message);
            using (var hmacsha256 = new HMACSHA256(keyByte))
            {
                byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
                return Convert.ToBase64String(hashmessage);
            }
        }

        /// <summary>
        /// wx统一下单请求数据
        /// </summary>
        /// <param name="URL">请求地址</param>
        /// <param name="urlArgs">参数</param>
        /// <returns></returns>
        private static string sendPost(string URL, string urlArgs)
        {
            
            System.Net.WebClient wCient = new System.Net.WebClient();
            wCient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
            //byte[] postData = System.Text.Encoding.ASCII.GetBytes(urlArgs);  如果微信签名中有中文会签名失败
  　　　　　　byte[] postData = System.Text.Encoding.UTF8.GetBytes(urlArgs);　　　　　
            byte[] responseData = wCient.UploadData(URL, "POST", postData);
　　　　　　　　
            string returnStr = System.Text.Encoding.UTF8.GetString(responseData);//返回接受的数据 
            return returnStr;
         }

        /// <summary>
        /// 生成订单号
        /// </summary>
        /// <returns></returns>
        private static string getRandomTime()
        {
            Random rd = new Random();//用于生成随机数
            string DateStr = DateTime.Now.ToString("yyyyMMddHHmmssMM");//日期
            string str = DateStr + rd.Next(10000).ToString().PadLeft(4, ‘0‘);//带日期的随机数
            return str;
        }

    }
}