在提交MVC4的视图中创建视图

Question

我有一个带有表单的视图，当提交该表单时，我想在第一个视图中显示另一个视图。我尝试过partialview（不确定是出于我的目的吗？）但是我无法让它工作，因为模型是null（它的强类型部分视图）。但我只是希望它在submitbutton上创建，然后就可以了。

因此，请在提交表单时帮助我创建一个视图/部分视图。现在我得到“对象引用未设置为对象的实例”。在我的局部视图中的foreach循环中，但是在提交表单之前不应该创建它。

我的观点：

<div class="calcInput">
                    @using (Html.BeginForm("ShowDetail", "Calculation"))
                    {
                       <div class="calculateBox">
                            <label for="calcOption">Choose value to calculate:</label>
                            <select form="anFormCalcInput" id="calcOption" title="Choose what value you want to calculate">
                                <option value="anPMT">Payment (PMT)</option>
                                <option value="anI">Interest (I)</option>
                                <option value="anFV">Future value (FV)</option>
                                <option value="anPV">Present value (PV)</option>
                            </select>
                        </div>
                        <div class="calculateBox" background-color="#777777">
                            @Html.Label("Present value (PV)")
                            @Html.TextBox("PresentValue")
                            @Html.Label("Future value")
                            @Html.TextBox("FutureValue")
                            @Html.Label("Interest rate")
                            @Html.TextBox("InterestRate") <br />
                            <input type="radio" name="advanceOrArrears" id="inAdvance" value="inAdvance" /> In advance<br />
                            <input type="radio" name="advanceOrArrears" id="inArrears" value="inArrears" /> In arrears
                        </div>
                        <div class="calculateBox">
                            <label for="startDate">Start date:</label>
                            <input type="date" id="anStartDate" name="startdate" title="Choose start date for your calculation" /><br />
                            @Html.Label("Payment frequency")
                            <select form="anFormCalcInput" id="anPmtFreq" title="Choose the payment frequency, for example: Every month">
                                <option value="Monthly">Monthly</option>
                                <option value="Quarterly">Quarterly</option>
                                <option value="Yearly">Yearly</option>
                            </select><br /><br />
                            @Html.Label("No of payment periods")
                            @Html.TextBox("PaymentPeriods")
                            @Html.Label("Date time convention")
                            <select form="anFormCalcInput" id="anDTC" title="Choose your Date time convention">
                                <option value="360360">360/360</option>
                                <option value="365365">365/365</option>
                            </select><br /><br />
                            <input type="submit" id="anCalcBtn" class="calcBtn" name="anSubmitBtn" value="Calculate" title="Calculate your calculation" />
                        </div>
                    }
                    </div>
                    <table cellspacing="0" width="80%">
                    <div class="calcGraph">
                    </div>
                    <div class="calcDetail" id="anCalcDetail">
                    @Html.Partial("ShowDetail") //This is where I want my view/partialview to show up
                    </div>

我的部分观点：

@model IEnumerable<CalcFactory.Models.Calculation>

<table cellspacing="0" width="80%">
<thead>
    <tr>
        <th>
            Date
        </th>
        <th>
            Invoice amount
        </th>
        <th>
            Interest rate
        </th>
        <th>
            Interest amount
        </th>
        <th>
            Amortization
        </th>
        <th>
            Capital balance
        </th>
        <th></th>
    </tr>
</thead>
<tr>
    <td align="center">
    </td>
    <td align="center">
    </td>
    <td align="center">
    </td>
    <td align="center">
    </td>
    <td align="center">
    </td>
    <td align="center" id="startValue">
    </td>
</tr>
@foreach (var item in Model) { //this is where i get null exception, model is null. But it supposed to be created on submit button...
<tr>
    <td>
        @Html.DisplayFor(modelItem => item.Date)
    </td>
    <td>
        @Html.DisplayFor(modelItem => item.InvoiceAmount)
    </td>
    <td>
        @Html.DisplayFor(modelItem => item.InterestRate)
    </td>
    <td>
        @Html.DisplayFor(modelItem => item.InterestAmount)
    </td>
    <td>
        @Html.DisplayFor(modelItem => item.Amortization)
    </td>
    <td>
        @Html.DisplayFor(modelItem => item.PresentValue)
    </td>
</tr>
}

我的控制器：

public class CalculationController : Controller
{
    public PartialViewResult ShowDetail(FormCollection form)
    {
        List<Calculation> cList = new List<Calculation>();
        Calculation calc = new Calculation();
        calc.Date = Convert.ToDateTime(form["startdate"]);
        calc.InvoiceAmount = 2000;
        calc.InterestRate = Convert.ToDouble(form["InterestRate"]);
        calc.InterestAmount = (Convert.ToDouble(form["PresentValue"]) * Convert.ToDouble(form["InterestRate"]) / 360 * 30);
        calc.Amortization = (2000 - (Convert.ToDouble(form["PresentValue"]) * Convert.ToDouble(form["InterestRate"]) / 360 * 30));
        calc.PresentValue = Convert.ToDouble(form["PresentValue"]) - calc.Amortization;
        cList.Add(calc);
        for (int i = 0; i < Convert.ToInt32(form["PaymentPeriods"]); i++)
        {
            Calculation calcBefore = cList.Last();
            calc = new Calculation();
            calc.Date = calcBefore.Date.AddMonths(1);
            calc.InvoiceAmount = 2000;
            calc.InterestRate = Convert.ToDouble(form["InterestRate"]);
            calc.InterestAmount = (calcBefore.PresentValue * Convert.ToDouble(form["InterestRate"]) / 360 * 30);
            calc.Amortization = (calc.InvoiceAmount - (calcBefore.PresentValue * calc.InterestRate / 360 * 30));
            calc.PresentValue = calcBefore.PresentValue - calc.Amortization;
            cList.Add(calc);
        }
        return PartialView("ShowDetail", cList);
    }
}