목록 제출은 게시물 + MVC에서 null이됩니다.

ViewModel이 있습니다.

public class RegistrationViewModel
{
    public string Country { get; set; }
    public ConfigurationParamValue CountryParam { get; set; }
    public string Civility { get; set; }
    public ConfigurationParamValue CivilityParam { get; set; }
    [FirstNameValidator(Category = "Registration", IsLocal = false )]
    public string FirstName { get; set; }
    public ConfigurationParamValue FirstNameParam { get; set; }
    [LastNameValidator(Category = "Registration", IsLocal = false)]
    public string LastName { get; set; }
    public List<int> Days { get; set; }
    public int SelectedDay{ get; set; }
    public List<Month> Months { get; set; }
    public Month SelectedMonth { get; set; }
    public List<int> Years { get; set; }
    public int SelectedYear { get; set; }
    public DateTime BirthDate { get; set; }
}

이 viewmodel로보기를 만듭니다.

@model Registration.Front.Web.Models.RegistrationViewModel

@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Index</h2>

@using (Html.BeginForm()) {
    @Html.AntiForgeryToken()
    @Html.ValidationSummary(true)

    <fieldset>
        <legend>RegistrationViewModel</legend>

        <div class="editor-label">
            @Html.LabelFor(model => model.Country)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Country)
            @Html.ValidationMessageFor(model => model.Country)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Civility)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Civility)
            @Html.ValidationMessageFor(model => model.Civility)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.FirstName)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.FirstName)
            @Html.ValidationMessageFor(model => model.FirstName)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.LastName)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.LastName)
            @Html.ValidationMessageFor(model => model.LastName)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.BirthDate)
        </div>
        <div class="editor-field">
            @Html.DropDownListFor(model => model.SelectedDay, new SelectList(Model.Days))
            @Html.ValidationMessageFor(model => model.BirthDate)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Occupation)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Occupation)
            @Html.ValidationMessageFor(model => model.Occupation)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.ZipCode)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.ZipCode)
            @Html.ValidationMessageFor(model => model.ZipCode)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Email)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Email)
            @Html.ValidationMessageFor(model => model.Email)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Password)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Password)
            @Html.ValidationMessageFor(model => model.Password)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.CGV)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.CGV)
            @Html.ValidationMessageFor(model => model.CGV)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Optin)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Optin)
            @Html.ValidationMessageFor(model => model.Optin)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.CNIL)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.CNIL)
            @Html.ValidationMessageFor(model => model.CNIL)
        </div>

        <p>
            <input type="submit" value="Create" />
        </p>
    </fieldset>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

이것은 내 컨트롤러입니다.

public ActionResult Index()
        {
        List<int> listDays = new List<int>(){1, 2, 3};
        return View(new RegistrationViewModel() { Days=listDays });
        }

[HttpPost]
public ActionResult Index( RegistrationViewModel rvm)
       {
       if (ModelState.IsValid)
          { return RedirectToAction("Welcome"); }

       return View(rvm);
       }

public ActionResult Welcome()
      {
      return View();
      }

내 문제는 게시물에 있습니다. viewmodel의 Days 속성이 null입니다 !!!!! 이 문제를 어떻게 해결할 수 있습니까?