为每个月的EMI重复整个日期列表

Question

我在试着做一个摊销时间表。我正在获取数据，但日期显示不正确。对于每个月的利息，所有日期(整个月列表)的本金和余额都会重复。这就是我所得到的

Date    Interest    Principal   Balance
6/04/2021 29        820          9180
6/05/2021 29        820          9180
6/06/2021 29        820          9180
....
6/04/2021 27        822          8358
6/05/2021 27        822          8358
6/06/2021 27        822          8358

对于下一个EMI，整个月份列表被重复，结果应该是这样的

Date    Interest    Principal   Balance
6/04/2021 29        820          9180
6/05/2021 27        822          8358

..。谢谢你的帮助。这是模型类

public class AmortizationSchedule
{
         [DisplayName("Start Date")]
        public DateTime StartDate{get;set;}
        public List<DateTime> Date { get; set; }
        public decimal Interest { get; set; }
        public decimal Balance { get; set; }
        public decimal Principal { get; set; }
}

这就是视图

@model IEnumerable<AmortizationCalculator.Web.Models.AmortizationSchedule>

<table>
    <thead>
        <tr>
            <th>Date</th>
            <th>Interest</th>
            <th>Principal</th>
            <th>Balance</th>

        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {

            @foreach (var q in item.Date)
            {
                <tr>
                    <td>
                        <li>@q.ToShortDateString()</li>

                    </td>
                    <td>
                        @item.Interest
                    </td>
                    <td>
                        @item.Principal
                    </td>
                    <td>
                        @item.Balance
                    </td>
                </tr>
                }
            }
        </tbody>

</table>

这些是我用来获得EMI的方法，以及开始日期和结束日期之间的月份列表

    public class AmortizedLib
    {

        public List<AmortizationSchedule> AmortizationScheduleCalculation(decimal totalAmount
        , decimal rate, decimal downPayment
            ,int loanTerm, DateTime startDate)
        {
            decimal EMI;
            decimal principal = totalAmount - downPayment;
            decimal monthlyInterest;
            decimal monthlyPrincipal;
            decimal newPrincipalBalance;
            int numberOfEMI = loanTerm * 12;
            int year = loanTerm * 12;

            DateTime Date = DateTime.Now;
            DateTime endDate = Date.AddMonths(year);

            Console.WriteLine(endDate);

            EMI = Math.Round(monthlyPayments(principal, rate, loanTerm));

            List<AmortizationSchedule> schedules = new List<AmortizationSchedule>();
            for (int i = 0; i <= numberOfEMI; i++)
            {
                monthlyInterest = Math.Round((principal * rate / 100) / 12);
                monthlyPrincipal = Math.Round(EMI - monthlyInterest);
                newPrincipalBalance = Math.Round(principal - monthlyPrincipal);
                principal = newPrincipalBalance;

                AmortizationSchedule amortizationSchedule = new AmortizationSchedule();

                    amortizationSchedule.Interest = monthlyInterest;
                    amortizationSchedule.Principal = monthlyPrincipal;
                    amortizationSchedule.Balance = newPrincipalBalance;
                    amortizationSchedule.Date = EachMonth(startDate, endDate, year).ToList();

                schedules.Add(amortizationSchedule);
            }

            return schedules;
        }

        // to calculate monthly EMI
        public static decimal monthlyPayments(decimal actualPrincipal, decimal rate, double loanTerm)
        {
            rate = rate / 1200;
            loanTerm = loanTerm * 12;
            decimal F = (decimal)Math.Pow((double)(1 + rate), loanTerm);
            return actualPrincipal * ((rate * F) / (F - 1));
        }

// to get the time list of  months
        public static IEnumerable<DateTime> EachMonth(DateTime startDate, DateTime endDate , int term)
        {
            int months = term;
            startDate = DateTime.Now.Date;
            endDate = startDate.AddMonths(months);


            for (var day = startDate.Date; day.Date <= endDate.Date; day = day.AddMonths(1))
                yield return day;
        }


    }


  [1]: https://i.stack.imgur.com/5bEo3.png

Answer 1

这个错误存在于模型以及calculationMethod中。模型不应该只有List的纯日期属性，foreach循环应该包含整个方法

public class AmortizationSchedule{
        public DateTime Date { get; set; }
        public decimal Interest { get; set; }
        public decimal Balance { get; set; }
        public decimal Principal { get; set; }
}

方法应该是

        public List<AmortizationSchedule> AmortizationScheduleCalculation(decimal totalAmount
        , decimal rate, decimal downPayment
            ,int loanTerm, DateTime startDate)
        {
            decimal EMI;
            decimal principal = totalAmount - downPayment;
            decimal monthlyInterest;
            decimal monthlyPrincipal;
            decimal newPrincipalBalance;
            int numberOfEMI = loanTerm * 12;
            int year = loanTerm * 12;

            DateTime Date = DateTime.Now;
            DateTime endDate = Date.AddMonths(year);

            Console.WriteLine(endDate);

            EMI = Math.Round(monthlyPayments(principal, rate, loanTerm));
            List<AmortizationSchedule> schedules = new List<AmortizationSchedule>();
            int i = 0;
            var monthlyDateList = EachMonth(startDate, endDate, year).ToList();
            foreach (var item in monthlyDateList)
            {
                monthlyInterest = Math.Round((principal * rate / 100) / 12);
                monthlyPrincipal = Math.Round(EMI - monthlyInterest);
                newPrincipalBalance = Math.Round(principal - monthlyPrincipal);
                principal = newPrincipalBalance;

                AmortizationSchedule amortizationSchedule = new AmortizationSchedule();
                amortizationSchedule.Date = item;
                amortizationSchedule.Interest = monthlyInterest;
                amortizationSchedule.Principal = monthlyPrincipal;
                amortizationSchedule.Balance = newPrincipalBalance;
                schedules.Add(amortizationSchedule);
                i++;
            }

            return schedules;

        }

视图应该是

<table>
    <thead>
        <tr>
            <th>Date</th>
            <th>Interest</th>
            <th>Principal</th>
            <th>Balance</th>

        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {
            <tr>
                <td>
                    @item.Date.ToShortDateString()
                </td>
                <td>
                    @item.Interest
                </td>
                <td>
                    @item.Principal
                </td>
                <td>
                    @item.Balance
                </td>

            </tr>
        }
        }
    </tbody>
</table>