Ienumerable é nulo quando espero valores

Question

Estou usando a abordagem neste artigo Para devolver uma lista de objetos que são postados em minha ação. Meu método se parece:

    //
    // POST: /LeaveRequest/Create
    [Authorize, HttpPost]
    public ActionResult Create(LeaveRequest leaveRequest, IEnumerable<DayRequested> requestedDays)
    {
        return RedirectToAction("Index", lrRepository.GetLeaveRequests(472940821));
    }

leaveRequest tem os dados que eu espero. requestedDays Contém o número de linhas que espero, mas todas as linhas contêm nulas em cada campo. Alguma idéia do que posso estar perdendo?

Aqui está o código de visualização:

Create.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<EmployeePayroll.ViewModels.LeaveRequestViewModel>" %>
<%@ Import Namespace="EmployeePayroll.Helpers"%>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">Create New Leave Request</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <h2>Create New Leave Request</h2>
    <div><%= Html.ActionLink("Back to List", "Index") %></div>
    <%= Html.Partial("RequestEditor", Model) %>
    <div><%= Html.ActionLink("Back to List", "Index") %></div>
</asp:Content>

Soliciteditor.ascx

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<EmployeePayroll.ViewModels.LeaveRequestViewModel>" %>
<% using (Html.BeginForm()) {%>
    <%= Html.ValidationSummary(true) %>
    <fieldset>
        <legend>Request Details</legend>
        <table>
             <tbody id="editorRows">
                <tr><th>Date</th><th>Time</th><th>Hours</th><th>Request Type</th><th></th></tr>
                <% foreach (var item in Model.DaysRequested)
                    Html.RenderPartial("RequestedDayRow", new EmployeePayroll.ViewModels.LeaveRequestRow(item, Model.LeaveRequestType)); %>
            </tbody>
        </table>
        <p><%= Html.ActionLink("Add Day", "BlankRequestedDayRow", null, new { id = "addItem" })%></p>

        <p>Type your time to sign your request.</p>
        <p><%= Html.LabelFor(model => model.LeaveRequest.EmployeeSignature) %>: <%= Html.TextBoxFor(model => model.LeaveRequest.EmployeeSignature, new { Class="required" })%></p>
        <p><%= Html.LabelFor(model => model.LeaveRequest.EmployeeComment) %>: <%= Html.TextBoxFor(model => model.LeaveRequest.EmployeeComment) %></p>
        <p><input type="submit" value="Submit Request" /></p>
    </fieldset>
<% } %>

SolicededdayDayrow.ascx

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<EmployeePayroll.ViewModels.LeaveRequestRow>" %>
<%@ Import Namespace="EmployeePayroll.Helpers"%>

<tr class="editorRow">
    <% using (Html.BeginCollectionItem("requestedDays"))
   { %>
        <td><%= Html.TextBoxFor(model => model.DayRequested.DateOfLeave, new { Class = "datepicker", Maxlength = "10" })%></td>
        <td><%= Html.TextBoxFor(model => model.DayRequested.TimeOfLeave, new { Class = "timedropdown", Maxlength = "8" })%></td>
        <td><%= Html.TextBoxFor(model => model.DayRequested.HoursRequested, new { Class = "hoursdropdown", Maxlength = "4" })%></td>
        <td><%= Html.DropDownListFor(model => model.DayRequested.RequestType, 
            new SelectList(Model.LeaveRequestType, "Value", "Text", Model.DayRequested.RequestType), "(Select)")%></td>
        <td><a href="#" class="deleteRow"><img src="../../images/site_icons/16/69.png" title="Delete" alt="Delete" border="0" /></a></td>
    <% } %>
</tr>

Aqui está o formulário gerado:

<form method="post" action="/LeaveRequest/Create">
    <fieldset>
        <legend>Request Details</legend>
        <table>
            <tbody id="editorRows">
                <tr><th>Date</th><th>Time</th><th>Hours</th><th>Request Type</th><th></th></tr>
<tr class="editorRow">
    <input type="hidden" value="c43391a3-7fe4-4514-8b27-d00995d64848" autocomplete="off" name="requestedDays.index">

        <td><input type="text" value="11/17/2010" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].DayRequested.DateOfLeave" id="requestedDays_c43391a3-7fe4-4514-8b27-d00995d64848__DayRequested_DateOfLeave" maxlength="10" class="datepicker"></td>
        <td><input type="text" value="8:00 AM" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].DayRequested.TimeOfLeave" id="requestedDays_c43391a3-7fe4-4514-8b27-d00995d64848__DayRequested_TimeOfLeave" maxlength="8" class="timedropdown"></td>
        <td><input type="text" value="8" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].DayRequested.HoursRequested" id="requestedDays_c43391a3-7fe4-4514-8b27-d00995d64848__DayRequested_HoursRequested" maxlength="4" class="hoursdropdown"></td>
        <td><select name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].DayRequested.RequestType" id="requestedDays_c43391a3-7fe4-4514-8b27-d00995d64848__DayRequested_RequestType"><option value="">(Select)</option>
</select></td>
        <td><a class="deleteRow" href="#"><img border="0" alt="Delete" title="Delete" src="../../images/site_icons/16/69.png"></a></td>
</tr>
<tr class="editorRow">
    <input type="hidden" value="a24b74f6-2947-4ec5-a817-f938d6fe4e24" autocomplete="off" name="requestedDays.index">
        <td><input type="text" value="11/17/2010" name="requestedDays[a24b74f6-2947-4ec5-a817-f938d6fe4e24].DayRequested.DateOfLeave" id="requestedDays_a24b74f6-2947-4ec5-a817-f938d6fe4e24__DayRequested_DateOfLeave" maxlength="10" class="datepicker"></td>
        <td><input type="text" value="8:00 AM" name="requestedDays[a24b74f6-2947-4ec5-a817-f938d6fe4e24].DayRequested.TimeOfLeave" id="requestedDays_a24b74f6-2947-4ec5-a817-f938d6fe4e24__DayRequested_TimeOfLeave" maxlength="8" class="timedropdown"></td>
        <td><input type="text" value="8" name="requestedDays[a24b74f6-2947-4ec5-a817-f938d6fe4e24].DayRequested.HoursRequested" id="requestedDays_a24b74f6-2947-4ec5-a817-f938d6fe4e24__DayRequested_HoursRequested" maxlength="4" class="hoursdropdown"></td>
        <td><select name="requestedDays[a24b74f6-2947-4ec5-a817-f938d6fe4e24].DayRequested.RequestType" id="requestedDays_a24b74f6-2947-4ec5-a817-f938d6fe4e24__DayRequested_RequestType"><option value="">(Select)</option>
</select></td>
        <td><a class="deleteRow" href="#"><img border="0" alt="Delete" title="Delete" src="../../images/site_icons/16/69.png"></a></td>
</tr>
</tbody>
    </table>
    <p><a id="addItem" href="/LeaveRequest/BlankRequestedDayRow">Add Day</a></p>

    <p>Type your time to sign your request.</p>
    <p><label for="LeaveRequest_EmployeeSignature">Employee Signature</label>: <input type="text" value="" name="LeaveRequest.EmployeeSignature" id="LeaveRequest_EmployeeSignature" class="required"></p>
    <p><label for="LeaveRequest_EmployeeComment">Employee Comment</label>: <input type="text" value="" name="LeaveRequest.EmployeeComment" id="LeaveRequest_EmployeeComment"></p>
    <p><input type="submit" value="Submit Request"></p>
</fieldset>
</form>

O formulário publica as seguintes informações:

Parametersapplication/x-www-form-urlencoded
LeaveRequest.EmployeeComm...    Comment
LeaveRequest.EmployeeSign...    Michael Wills
requestedDays.index 549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2
requestedDays.index 2838b025-d971-4d98-a081-5ea0c559aebb
requestedDays[2838b025-d9...    11/17/2010
requestedDays[2838b025-d9...    8
requestedDays[2838b025-d9...    1
requestedDays[2838b025-d9...    8:00 AM
requestedDays[549a7c9a-9c...    11/17/2010
requestedDays[549a7c9a-9c...    8
requestedDays[549a7c9a-9c...    1
requestedDays[549a7c9a-9c...    8:00 AM
Source
Content-Type: application/x-www-form-urlencoded
Content-Length: 907
requestedDays.index=549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2&requestedDays%5B549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2%5D.DayRequested.DateOfLeave=11%2F17%2F2010&requestedDays%5B549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2%5D.DayRequested.TimeOfLeave=8%3A00+AM&requestedDays%5B549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2%5D.DayRequested.HoursRequested=8&requestedDays%5B549a7c9a-9c7d-4032-a1cd-6bfda92bf1f2%5D.DayRequested.RequestType=1&requestedDays.index=2838b025-d971-4d98-a081-5ea0c559aebb&requestedDays%5B2838b025-d971-4d98-a081-5ea0c559aebb%5D.DayRequested.DateOfLeave=11%2F17%2F2010&requestedDays%5B2838b025-d971-4d98-a081-5ea0c559aebb%5D.DayRequested.TimeOfLeave=8%3A00+AM&requestedDays%5B2838b025-d971-4d98-a081-5ea0c559aebb%5D.DayRequested.HoursRequested=8&requestedDays%5B2838b025-d971-4d98-a081-5ea0c559aebb%5D.DayRequested.RequestType=1&LeaveRequest.EmployeeSignature=Michael+Wills&LeaveRequest.EmployeeComment=Comment

Answer 1

Parece que você pode precisar remover DayRequested do seu nome de campo de formulário oculto.

Por exemplo:

... I removed some of the attributes because the only thing that's changed here is the name attribute.
<input type="hidden" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].DateOfLeave" value="11/17/2010" />
<input type="hidden" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].TimeOfLeave" value="8:00 AM" />
<input type="hidden" name="requestedDays[c43391a3-7fe4-4514-8b27-d00995d64848].HoursRequested" value="8"  />
...

Conforme discutido na pergunta comentários, parece estranho que o ASP.NET MVC gerasse a fonte que você deu, pois isso sugere que cada um RequestedDay Objeto tem uma única propriedade chamada RequestedDay.

O objeto que você está vinculativo é chamado requestedDays, e o GUID é uma indicação de qual posição na coleção você está vinculando (declarando o óbvio aqui, eu sei!). Portanto, declarando o nome do objeto (DayRequested) não faz sentido, já que o fichário do modelo já deve saber disso e só precisa saber com qual propriedade dessa classe está lidando.

Answer 2

Veja este post de Haacked - Modelo Ligação a uma listaPode te ajudar