C#微信开发之旅(十)：APP预支付及支付参数生成(V2)

App支付流程：

本篇随笔只实现红框内的两个功能：生成预支付Id，生成app支付参数

 　　    /// <summary>
        /// App 预支付
        /// </summary>
        /// <returns></returns>
        public ActionResult AppPrePay()
        {
            string orderNo = ""; //订单编号，文档中的out_trade_no
            string description = ""; //订单详情
            string totalFee = "";//订单金额（单位：分）
            string notifyUrl = ""; //支付通知Url
            string createIp = "";//用户IP

            string traceId = string.Empty; //

            WxPayModel model = WxPayModel.Create(description, orderNo, totalFee, notifyUrl, createIp);
            //预支付
            var result = WeiXinHelper.PreWXPay(model.CreateAppPrePayPackage(traceId));

            if (!string.IsNullOrEmpty(result.PrePayId))
            {
                Response.Write("预支付ID：" + result.PrePayId);
            }
            else
            {
                Response.Write("预支付失败！");
            }

            //生成app支付json
            string appPayJson = model.CreateAppPayPackage(result.PrePayId);

            Response.Write("app支付Json:" + appPayJson);

            return View();
        }

下面是生成预支付json 和 app支付json的方法（均通过实际测试，可放心使用）：

        /// <summary>
        /// 生成app预支付请求json（已测试通过）
        /// </summary>
        /// <param name="traceid">交易号：自定义，可用于订单的查询和跟踪，建议根据支付用户信息生成此Id</param>
        /// <returns></returns>
        /// <remarks>
        ///* { "appid":"wwwwb4f85f3a797777", "traceid":"crestxu",
        ///* "noncestr":"111112222233333", "package":
        ///* "bank_type=WX&body=XXX&fee_type=1&input_charset=GBK&notify_url=http%3a%2f%2f
        ///* www
        ///* .qq.com&out_trade_no=16642817866003386000&partner=1900000109&spbill_create_ip
        ///* =127.0.0.1&total_fee=1&sign=BEEF37AD19575D92E191C1E4B1474CA9",
        ///* "timestamp":1381405298,
        ///* "app_signature":"53cca9d47b883bd4a5c85a9300df3da0cb48565c",
        ///* "sign_method":"sha1" }
        /// </remarks>
        public string CreateAppPrePayPackage(string traceid)
        {
            Dictionary<string, string> nativeObj = new Dictionary<string, string>();
            if (CheckCftParameters() == false)
            {
                throw new SDKRuntimeException("生成package参数缺失！");
            }
            nativeObj.Add("appid", AppId);
            nativeObj.Add("package", GetCftPackage());
            nativeObj.Add("timestamp", ((DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000).ToString());
            nativeObj.Add("traceid", traceid);
            nativeObj.Add("noncestr", CommonUtil.CreateNoncestr());
            nativeObj.Add("app_signature", GetBizSign(nativeObj));
            nativeObj.Add("sign_method", SignType);

            var entries = nativeObj.Select(d => string.Format(""{0}": "{1}"", d.Key, d.Value));

            return "{" + string.Join(",", entries.ToArray()) + "}";
        }

        /// <summary>
        /// 生成app支付请求json（已测试通过）
        /// </summary>
        /// <param name="prepayid">预支付id</param>
        /// <returns></returns>
        /// <remarks>
        /// { 
        /// "appid":"wwwwb4f85f3a797777",
        /// "noncestr":"111112222233333", 
        /// "package":"Sign=WXpay",
        /// "partnerid":"1900000109",
        /// "prepayid":"1101000000140429eb40476f4c9",
        /// "sign":"53cca9d47b883bd4a5c85a9300df3da0cb48565c",
        /// "timestamp":1381405298,
        ///  }
        /// </remarks>
        public string CreateAppPayPackage(string prepayid)
        {
            Dictionary<string, string> nativeObj = new Dictionary<string, string>();
            if (CheckCftParameters() == false)
            {
                throw new SDKRuntimeException("生成package参数缺失！");
            }
            nativeObj.Add("appid", AppId);
            nativeObj.Add("noncestr", CommonUtil.CreateNoncestr());
            nativeObj.Add("package", "Sign=WXPay");
            nativeObj.Add("partnerid", GetPartnerId());
            nativeObj.Add("prepayid", prepayid);
            nativeObj.Add("timestamp", ((DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000).ToString());
            nativeObj.Add("sign", GetBizSign(nativeObj));

            var entries = nativeObj.Select(d => string.Format(""{0}": "{1}"", d.Key, d.Value));

            return "{" + string.Join(",", entries.ToArray()) + "}";
        }