C# LINQ行转列输出年度报表、月度汇总报表、应收明细汇总表

    /// <summary>
    /// 应收明细汇总表-数据项
    /// </summary>
    public class res_ARSummaryItem
    {

        public string CustomerCode { get; set; }
        public string CustomerName { get; set; }

        /// <summary>
        /// 年
        /// </summary>
        public int Year { get; set; }

        /// <summary>
        /// 月
        /// </summary>
        public int Month { get; set; }

        /// <summary>
        /// 月份, 如：2023/06
        /// </summary>
        public string YearMonth { get; set; }

        /// <summary>
        /// 货币
        /// </summary>
        public string CurrencyCode { get; set; }

        /// <summary>
        /// 订单金额
        /// </summary>
        public decimal AmountOrder { get; set; }

        /// <summary>
        /// 已收金额
        /// </summary>
        public decimal AmountPaid { get; set; }

        /// <summary>
        /// 未收金额
        /// </summary>
        public decimal AmountBalance { get; set; }        
    }

        /// <summary>
        /// 应收明细汇总表(行转列)
        /// </summary>
        /// <param name="year">年度，报表必选条件</param>
        /// <param name="listSource">数据源，行数据</param>
        /// <returns></returns>
        public List<res_ARSummary> GetARSummaryRowToCol(int year, List<res_ARSummaryItem> listSource)
        {
            //过来年度数据
            listSource = listSource.Where(w => w.Year == year).ToList();

            var q = (from a in listSource
                     group a by new { a.CustomerCode, a.CustomerName, a.CurrencyCode })
                    .Select(s => new res_ARSummary
                    {
                        ID = 0,
                        CustomerCode = s.Key.CustomerCode,
                        CustomerName = s.Key.CustomerName,
                        CurrencyCode = s.Key.CurrencyCode,

                        M01Amount = s.Where(w => w.Month == 1).Sum(s => s.AmountOrder),
                        M01Paied = s.Where(w => w.Month == 1).Sum(s => s.AmountPaid),
                        M01Balance = s.Where(w => w.Month == 1).Sum(s => s.AmountBalance),

                        M02Amount = s.Where(w => w.Month == 2).Sum(s => s.AmountOrder),
                        M02Paied = s.Where(w => w.Month == 2).Sum(s => s.AmountPaid),
                        M02Balance = s.Where(w => w.Month == 2).Sum(s => s.AmountBalance),

                        M03Amount = s.Where(w => w.Month == 3).Sum(s => s.AmountOrder),
                        M03Paied = s.Where(w => w.Month == 3).Sum(s => s.AmountPaid),
                        M03Balance = s.Where(w => w.Month == 3).Sum(s => s.AmountBalance),

                        M04Amount = s.Where(w => w.Month == 4).Sum(s => s.AmountOrder),
                        M04Paied = s.Where(w => w.Month == 4).Sum(s => s.AmountPaid),
                        M04Balance = s.Where(w => w.Month == 4).Sum(s => s.AmountBalance),

                        M05Amount = s.Where(w => w.Month == 5).Sum(s => s.AmountOrder),
                        M05Paied = s.Where(w => w.Month == 5).Sum(s => s.AmountPaid),
                        M05Balance = s.Where(w => w.Month == 5).Sum(s => s.AmountBalance),

                        M06Amount = s.Where(w => w.Month == 6).Sum(s => s.AmountOrder),
                        M06Paied = s.Where(w => w.Month == 6).Sum(s => s.AmountPaid),
                        M06Balance = s.Where(w => w.Month == 6).Sum(s => s.AmountBalance),

                        M07Amount = s.Where(w => w.Month == 7).Sum(s => s.AmountOrder),
                        M07Paied = s.Where(w => w.Month == 7).Sum(s => s.AmountPaid),
                        M07Balance = s.Where(w => w.Month == 7).Sum(s => s.AmountBalance),

                        M08Amount = s.Where(w => w.Month == 8).Sum(s => s.AmountOrder),
                        M08Paied = s.Where(w => w.Month == 8).Sum(s => s.AmountPaid),
                        M08Balance = s.Where(w => w.Month == 8).Sum(s => s.AmountBalance),

                        M09Amount = s.Where(w => w.Month == 9).Sum(s => s.AmountOrder),
                        M09Paied = s.Where(w => w.Month == 9).Sum(s => s.AmountPaid),
                        M09Balance = s.Where(w => w.Month == 9).Sum(s => s.AmountBalance),

                        M10Amount = s.Where(w => w.Month == 10).Sum(s => s.AmountOrder),
                        M10Paied = s.Where(w => w.Month == 10).Sum(s => s.AmountPaid),
                        M10Balance = s.Where(w => w.Month == 10).Sum(s => s.AmountBalance),

                        M11Amount = s.Where(w => w.Month == 11).Sum(s => s.AmountOrder),
                        M11Paied = s.Where(w => w.Month == 11).Sum(s => s.AmountPaid),
                        M11Balance = s.Where(w => w.Month == 11).Sum(s => s.AmountBalance),

                        M12Amount = s.Where(w => w.Month == 12).Sum(s => s.AmountOrder),
                        M12Paied = s.Where(w => w.Month == 12).Sum(s => s.AmountPaid),
                        M12Balance = s.Where(w => w.Month == 12).Sum(s => s.AmountBalance),

                    });

            var result = q.ToList();

            result.ForEach(i =>
            {
                i.TotalBalance = i.M01Balance + i.M02Balance + i.M03Balance + i.M04Balance + i.M05Balance + i.M06Balance
                + i.M07Balance + i.M08Balance + i.M09Balance + i.M10Balance + i.M11Balance + i.M12Balance;
            });

            return result;
        }