【微信支付】公众号 JSAPI支付 HTML5(使用MUI前端框架)+WebApi 实现流程

必要参数： 

    1） AppID，AppSecret : 在微信公众号后台管理—>(菜单栏)开发 —> 基本设置

    2）商户号 ：在微信公众号后台管理—>(菜单栏)微信支付—> 商户号管理

     

    3）商户秘钥 ：在微信商户平台（可直接点击上图的“查看”）商户平台 —> 产品中心 —> 开发配置

 基本配置：

      1）IP白名单：a.测试电脑的ip地址，b.存放WebApi的服务器电脑ip地址

    2）商户平台-->产品中心-->开发配置-->支付配置-->公众号支付：支付授权目录

注：  a.前端页面的地址 b.后台支付方法的地址(都是域名而不是IP)

具体步骤：

    1）添加充值按钮

<div class="mui-content-padded" style="margin-top: 6%;">
    <button id='login' class="mui-btn mui-btn-block mui-btn-primary">充值</button>
</div>

  2）引用js

       获取当前设备的IP地址： <script type="text/javascript" src="http://pv.sohu.com/cityjson?ie=utf-8"></script>         

3）获取code  ，openid     

注：redirect_uri：是返回当前页面的 url,code的值会追加在这个地址后面，所以可以根据url的地址截取到需要的code值（如果有需要加的参数，可以直接写在后面，如标记的一样）

(function($) {
            $.init();
            var url = location.search;
            var str = url.substr(1);
            code = str.split('code=')[1].split('&')[0];
           //页面加载时，判断code有没有值，没有就访问 获取if (code == 'null') {
                var numberurl = cardnumber + "=" + id;
                window.location.href =
                    "https://open.weixin.qq.com/connect/oauth2/authorize?appid=（是你的AppID）&redirect_uri=http://llcz.jolinmind.com/taocan.html?number=" +
                    numberurl + "&id=" + id + "&response_type=code&scope=snsapi_base&state=STATE&connect_redirect=1#wechat_redirect";

            } else {
                var codeN = code;
                mui.ajax({
                    url: '……/api/pay/get?jsoncallback=?',
                    data: {
                        code: codeN
                    },
                    async: true,
                    dataType: 'json',
                    crossDomain: true,
                    type: 'get',
                    timeout: 10000,
                    success: function(data) {
                        openid=data;
                     },
                 });
            }

        })(mui);

   后台Webapi：

   _appid =AppID ，_secret =AppSecret 

  public object Get(string code)
        {
            string html = string.Empty;
            string url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid="+ _appid + "&secret="+ _secret + "&code="+ code + "&grant_type=authorization_code";
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method = "GET";
            request.ContentType = "text/html;charset=UTF-8";
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            Stream ioStream = response.GetResponseStream();
            StreamReader sr = new StreamReader(ioStream, Encoding.UTF8);
            html = sr.ReadToEnd();
            sr.Close();
            ioStream.Close();
            response.Close();
            RepParamrepCode rep = JsonConvert.DeserializeObject<RepParamrepCode>(html);
            return rep.openid;

        }

        public class RepParamrepCode
        {
            public string access_token { get; set; }
            public string expires_in { get; set; }
            public string refresh_token { get; set; }
            public string openid { get; set; }
            public string scope { get; set; }
        }

     4）支付

    document.getElementById("login").addEventListener('tap', function() {
            getCode();
        });function getCode() {
                mui.ajax({
                            url: '……/api/pay/get?jsoncallback=?',
                            data: {
                                openid: openid,
                                motto: returnCitySN.cip,(当前设备的IP地址)
                                xufei: （支付金额）
                            },
                            async: true,
                            dataType: 'json',
                            crossDomain: true,
                            type: 'get',
                            timeout: 10000,
                            success: function(res) {                         
                                 if (typeof WeixinJSBridge == "undefined") {
                                    if (document.addEventListener) {
                                        document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);
                                    } else if (document.attachEvent) {
                                        document.attachEvent('WeixinJSBridgeReady', onBridgeReady);
                                        document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);
                                    }
                                } else {
                                    onBridgeReady(res)
                                }
                            }
                        });
                 }
          }
        function onBridgeReady(data) {     
            var list = JSON.parse(data);
            WeixinJSBridge.invoke(
                'getBrandWCPayRequest', {
                    "appId": （你的AppId）,
                    "timeStamp": list['timeStamp'], //时间戳，自1970年以来的秒数
                    "nonceStr": list['nonceStr'], //随机串
                    "package": list['package1'],
                    "signType": list['signType'], //微信签名方式:
                    "paySign": list['paySign'] //微信签名
                },
                function(res) {
                    if (res.err_msg == "get_brand_wcpay_request:ok") {
                       操作成功后，你自己的方法。

                    } else if (res.err_msg == "get_brand_wcpay_request:cancel") {
                        mui.alert('取消支付！', '提示');                    

                    } else {
                        mui.alert('支付失败！', '提示');
                    }
                });
        }

  后台Webapi：

  public string Get(string openid, string motto, int xufei)
        {
            return Getprepay_id(_appid, _mch_id, GetRandomString(),"抬头", getRandomTime(), xufei, motto, "http://……/api/OM/get（支付成功后验证数据库是否有数据的地址）", openid);

        }
        //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 mch_id, string nonce_str, string body,string out_trade_no,int total_fee, string spbill_create_ip ,string notify_url, string openid)
        {
            var url = "https://api.mch.weixin.qq.com/pay/unifiedorder";//微信统一下单请求地址

            string strA = "appid=" + appid + "&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=JSAPI";

            string strk = strA + "&key=" + _key; //key为商户平台设置的密钥key(假)
            string strMD5 = MD5(strk).ToUpper();//签名
            var formData = "<xml>";
            formData += "<appid>" + appid + "</appid>";//appid
            formData += "<body>" + body + "</body>";
            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>";
            formData += "<openid>" + openid + "</openid>";
            formData += "<out_trade_no>" + out_trade_no + "</out_trade_no>";
            formData += "<spbill_create_ip>" + spbill_create_ip + "</spbill_create_ip>";//终端IP --用户ip
            formData += "<total_fee>" + total_fee + "</total_fee>";
            formData += "<trade_type>JSAPI</trade_type>";//交易类型(JSAPI--公众号支付)
            formData += "<sign>" + strMD5 + "</sign>"; //签名
            formData += "</xml>";
            string v = sendPost(url, formData);
            string prepay_id = v;
            //时间戳
            string _time = getTime().ToString();

            string strB = "appId=" + appid + "&nonceStr=" + nonce_str + "&package=prepay_id=" + prepay_id + "&signType=MD5&timeStamp=" + _time + "&key=" + _key;
            wx w = new wx();
            w.timeStamp = _time;
            w.nonceStr = nonce_str;
            w.package1 = "prepay_id=" + prepay_id;
            w.paySign = MD5(strB).ToUpper();
            w.signType = "MD5";
            return JsonConvert.SerializeObject(w);
        }

        private static string sendPost(string postUrl, string menuInfo)
        {
            string returnValue = string.Empty;
            byte[] byteData = Encoding.UTF8.GetBytes(menuInfo);
            Uri uri = new Uri(postUrl);
            HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(uri);
            webReq.Method = "POST";
            webReq.ContentType = "application/x-www-form-urlencoded";
            webReq.ContentLength = byteData.Length;
            //定义Stream信息
            Stream stream = webReq.GetRequestStream();
            stream.Write(byteData, , byteData.Length);
            stream.Close();
            //获取返回信息
            HttpWebResponse response = (HttpWebResponse)webReq.GetResponse();
            StreamReader streamReader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            returnValue = streamReader.ReadToEnd();
            //关闭信息
            streamReader.Close();
            response.Close();
            stream.Close();

            XmlDocument doc = new XmlDocument();
            doc.LoadXml(returnValue);
            XmlNodeList list = doc.GetElementsByTagName("xml");
            XmlNode xn = list[];
            string prepay_ids = xn.SelectSingleNode("//prepay_id").InnerText;
            return prepay_ids;

        }

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

            return byte2String;
        }

        /// <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().ToString().PadLeft(, '');//带日期的随机数
            return str;
        }

        /// <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 < )
                return string.Empty;

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

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

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

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

                while (result >  && sb.Length < length)
                {
                    index = (int)(bit & result);
                    sb.Append(key[index]);
                    result = result >> ;
                }
            }
            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(, , )));
            long t = (long)cha.TotalSeconds;
            return t;
        }

微信支付接口签名验证工具：

  https://pay.weixin.qq.com/wiki/doc/api/micropay.php?chapter=20_1