計算Linq中的運行總計

Question

我正在嘗試計算兩列的余額。 我嘗試了很多方法，但是沒有運氣。

例如：

我想得到這樣的結果：

借方 貸方 余額
===== ====== =======
125.00 0.00 125.00
236.00 0.00 361.00
0.00 100.00 261.00

我的密碼

var filteredSales = (from av in db.AccountVouchers
            join l in db.Ledgers on new {LedgerID = (Int32) av.LedgerID} equals new     {LedgerID = l.LedgerID}
            join sm in db.SalesMasters on av.VoucherNo equals sm.BillNo.ToString()
            where (av.VoucherDate >= FromDate && av.VoucherDate <= ToDate && av.LedgerID == LedgerID)
            group new {av, l, sm} by new
            {
                av.VoucherDate,
                l.LedgerName,
                av.VoucherType,
                av.VoucherNo,
                sm.REFNO,
                av.Debit,
                av.Credit,
                av.Narration
            }
            into g
            select new
            {

                g.Key.VoucherDate,
                g.Key.LedgerName,
                g.Key.VoucherType,
                VoucherNo = (g.Key.VoucherType != "SALES" ? g.Key.REFNO : g.Key.VoucherNo),
                //g.Key.VoucherNo,
                g.Key.Debit,
                g.Key.Credit,
                g.Key.Narration,
                dSum = g.Sum(s => s.av.Debit),

                //Balance=g.Key.Debit-g.Key.Credit,

              //  TBal = int.Parse(TBal) + (g.Key.Debit != 0 ? TBal + g.Key.Debit : TBal - g.Key.Credit))


                             }).ToList();

Answer 1

終於，我明白了你的問題：

void Main()
{
    var list=new List<test>
    {
      new test{ Debit=125, Credit=0},
      new test{ Debit=236,Credit=0},
      new test{ Debit=0, Credit=100},
    };
    if(list.Any())
    {
       var first = list.First();
       first.Balance = first.Debit - first.Credit;
       list.Aggregate((x,y)=>{ y.Balance = x.Balance + y.Debit - y.Credit; return y;});
    }

    list.Dump();
}
class test
{
   public int Debit {get;set;}
   public int Credit {get;set;}
   public int Balance {get;set;}
}

Answer 2

這顯示了Tim示例的替代語法。

void Main()
{
    var list=new List<test>
    {
      new test{ Debit=125, Credit=0},
      new test{ Debit=236,Credit=0},
      new test{ Debit=0, Credit=100},
    };
    int balance = 0;
    list = list.Select( i=> { 
        balance += i.Debit - i.Credit;
        i.Balance = balance;
        return i;
        }).ToList();
    list.Dump();
}
class test
{
   public int Debit {get;set;}
   public int Credit {get;set;}
   public int Balance {get;set;}
}

這是從這里得出的答案中得出的。 正如注釋中提到的那樣，您應該注意不要使執行多次發生，因為余額值會關閉。 使用ToList（）應該注意這一點。

Answer 3

更簡單的解決方案：

var result=accountVouchers.Select((x, i) => new AccountVoucher { Debit = x.Debit, Credit = x.Credit, Balance = list.Take(i+1).Sum(y => y.Debit - y.Credit) });

完整的代碼：

using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var accountVouchers= new List<AccountVoucher>
            {
                new AccountVoucher{ Debit=125, Credit=0},
                new AccountVoucher{ Debit=236,Credit=0},
                new AccountVoucher{ Debit=0, Credit=100},
            };
            var result=accountVouchers.Select((x, i) => new AccountVoucher { Debit = x.Debit, Credit = x.Credit, Balance = list.Take(i+1).Sum(y => y.Debit - y.Credit) });
        }
    }
    class AccountVoucher
    {
        public int Debit { get; set; }
        public int Credit { get; set; }
        public int Balance { get; set; }
    }
}