MVC字符串转json,ajax接受json返回值

#region 功能
        /// <summary>
        /// 查询 微信用户一定年月的账单
        /// </summary>
        /// <param name="year">年，最多4个字符</param>
        /// <param name="month">月，最多2个字符</param>
        /// <returns></returns>
        public JsonResult YearDay(string year, string month)
        {
            if (UserStatus() == true)
            {
                #region 查询账单
                string sql = "SELECT Q054,Q055,Q056,Q057,Q058,Q062,Q063,Q064,Q065,Q066,Q067,Q068,Q069,Q070,Q071,Q072,Q073,Q074,Q075 FROM skt75 where Q057 = '" + userid().Community2 + "' and Q058 = '" + userid().Community + "' and Q056= '" + year + "-" + month + "' ";
                MySqlConnection con = new MySqlConnection("server=012.345.678.901;port=0123;User Id=UId;password=Pwd;database=DB");
                MySqlDataAdapter da = new MySqlDataAdapter(sql, con);
                DataSet ds = new DataSet();
                da.Fill(ds);
                DataTable dts = ds.Tables[0];
                if (dts.Columns.Count > 0)
                {
                    try
                    {
                        string Q063 = (dts.Rows[0]["Q063"].ToString() == "False" ? "否" : "是");
                        string str = "{ 'Q054': '" + dts.Rows[0]["Q054"].ToString() + "'," +
                            "'Q055':'" + dts.Rows[0]["Q055"].ToString() + "'," +
                            "'Q062':'" + dts.Rows[0]["Q062"].ToString() + "'," +
                            "'Q063':'" + Q063 + "'," +
                            "'Q064':'" + dts.Rows[0]["Q064"].ToString() + "'," +
                            "'Q065':'" + dts.Rows[0]["Q065"].ToString() + "'," +
                            "'Q066':'" + dts.Rows[0]["Q066"].ToString() + "'," +
                            "'Q067':'" + dts.Rows[0]["Q067"].ToString() + "'," +
                            "'Q068':'" + dts.Rows[0]["Q068"].ToString() + "'," +
                            "'Q069':'" + dts.Rows[0]["Q069"].ToString() + "'," +
                            "'Q070':'" + dts.Rows[0]["Q070"].ToString() + "'," +
                            "'Q071':'" + dts.Rows[0]["Q071"].ToString() + "'," +
                            "'Q072':'" + dts.Rows[0]["Q072"].ToString() + "'," +
                            "'Q073':'" + dts.Rows[0]["Q073"].ToString() + "'," +
                            "'Q074':'" + dts.Rows[0]["Q074"].ToString() + "'," +
                            "'Q075':'" + dts.Rows[0]["Q075"].ToString() + "'," +
                            "'Q056':'" + dts.Rows[0]["Q056"].ToString() + "'" +
                            "}";
                        ViewBag.fang = userid().Community;
                        return Json(str.Replace('\'', '"'));
                    }
                    catch
                    {
                        string str = "{ " +
                            "'Q054':'暂无信息'," +
                            "'Q055':'暂无信息'," +
                            "'Q062':'暂无信息'," +
                            "'Q063':'暂无信息'," +
                            "'Q064':'暂无信息'," +
                            "'Q065':'暂无信息'," +
                            "'Q066':'暂无信息'," +
                            "'Q067':'暂无信息'," +
                            "'Q068':'暂无信息'," +
                            "'Q069':'暂无信息'," +
                            "'Q070':'暂无信息'," +
                            "'Q071':'暂无信息'," +
                            "'Q072':'暂无信息'," +
                            "'Q073':'暂无信息'," +
                            "'Q074':'暂无信息'," +
                            "'Q075':'暂无信息'," +
                            "'Q056':'暂无信息'" +
                            "}";
                        ViewBag.fang = userid().Community;
                        return Json(str.Replace('\'', '"'));
                    }
                }
                else
                {
                    string str = "{ " +
                           "'Q054':'暂无信息'," +
                           "'Q055':'暂无信息'," +
                           "'Q062':'暂无信息'," +
                           "'Q063':'暂无信息'," +
                           "'Q064':'暂无信息'," +
                           "'Q065':'暂无信息'," +
                           "'Q066':'暂无信息'," +
                           "'Q067':'暂无信息'," +
                           "'Q068':'暂无信息'," +
                           "'Q069':'暂无信息'," +
                           "'Q070':'暂无信息'," +
                           "'Q071':'暂无信息'," +
                           "'Q072':'暂无信息'," +
                           "'Q073':'暂无信息'," +
                           "'Q074':'暂无信息'," +
                           "'Q075':'暂无信息'," +
                           "'Q056':'暂无信息'" +
                           "}";
                    ViewBag.fang = userid().Community;
                    return Json(str.Replace('\'', '"'));
                }
                #endregion
            }
            else
            {
                return Json("未认证或认证未通过");
            }
        }
        #endregion

$.ajax({
                type: 'post',
                url: '/Home/YearDay',
                data: { "year": year, "month": month },
                success: function (msg) {
                    msg = JSON.parse(msg)
                    console.log(msg)
                    
                    $("#Amount").text("￥" + msg.Q071);//应缴合计
                    $("#Rent").text("￥" + msg.Q062);//租金
                    $("#PropertyFee").text("￥" + msg.Q064);//管理费
                    $("#WaterRate").text("￥" + msg.Q066);//水费
                    $("#PoolwaterFee").text("￥" + msg.Q067);//月水电分摊
                    $("#LightingElectricity").text("￥" + msg.Q065);//月电费
                    $("#MaintenanceCost").text("￥" + msg.Q068);//维修费
                    $("#OverdueFine").text("￥" + msg.Q069);//滞纳金

                    $("#TCLElectricity").text(msg.Q063);//是否含税
                    $("#PublicElectricity").text(msg.Q072);//应缴时间
                    $("#AirOvertime").text("￥" + msg.Q070);//总合计
                }
            })