无法在mvc 5中绑定一组radiobuttons

Question

我在mvc 5上做了一个反馈表，反馈表由10个问题组成，每个问题有5个选定答案。这些选定的答案是我填充的单选按钮组。但是在post action方法中，单选按钮没有绑定。以下是我的代码。

Model.cs

public class FeedbackForm
    {
        public string Id { get; set; }
        public Models.Questionnaire mquestions { get; set; }
        public List<Questionnaire> Question { get; set; }
        public Batches batches { get; set; }
        public User user { get; set; }
        public DateTime Datetime { get; set; }


    }

    public class Questionnaire
    {
        public string QuestionId { get; set; }
        public string QuestionTitle { get; set; }
        [Required]
        public int? SelectedAnswer { get; set; } // for binding
        public IEnumerable<QuestionnaireStatus> PossibleAnswers { get; set; }
    }

    public class QuestionnaireStatus
    {
        public string StatusId { get; set; }
        public string StatusTitle { get; set; }
    }

Controller.cs

public ActionResult Index()
        {
            List<Models.FeedbackForm> lstfeedback = new List<Models.FeedbackForm>();
            Models.FeedbackForm form = new Models.FeedbackForm();


            Context.FeedBackForm contFeedback = new Context.FeedBackForm();

            Models.FeedbackForm vm = new Models.FeedbackForm();

            form.Question = new List<Models.Questionnaire>();
            form.Question = contFeedback.GetAllQuestionnaire();

            for (int i = 0; i < form.Question.Count; i++)
            {

                lstfeedback.Add(new Models.FeedbackForm
                {
                    Question = new List<Models.Questionnaire>()
                    { new Models.Questionnaire
                    {
                        QuestionId = form.Question[i].QuestionId,
                        QuestionTitle = form.Question[i].QuestionTitle
                    ,
                        PossibleAnswers = contFeedback.GetAllStatus()
                    },

                }
                });
            }


            return View(lstfeedback);
        }

View.cshtml

@using (Html.BeginForm())
{
    <table class="table">
        <tr>
            <th>
                @*@Html.Display("Questions")*@
            </th>

            @for (int i = 0; i < Model.Count; i++)
            {
                for (int j = 0; j < Model[i].Question.Count; j++)
                {

                        foreach (var item in Model[i].Question[j].PossibleAnswers)
                        {
                            <th>
                                @item.StatusTitle
                            </th>

                        }
                    break;
                }
                break;
            }

        </tr>

        @for (int i = 0; i < Model.Count; i++)
        {
            <tr>

                @for (int j = 0; j < Model[i].Question.Count; j++)
                {
                    <td>
                        @Html.DisplayFor(m=>Model[i].Question[j].QuestionTitle)
                    </td>

                    foreach (var item in Model[i].Question[j].PossibleAnswers)
                    {
                        <td>
                            @Html.RadioButtonFor(m => Model[i].Question[j].SelectedAnswer, item.StatusId, new { id = item.StatusId })
                        </td>
                    }

                    @Html.ValidationMessageFor(m => Model[i].Question[j].SelectedAnswer)

                }

            </tr>
        }

    </table>
    <div class="form-group">
        <div class="col-md-10">
            <input type="submit" id="Attendance" value="Submit" class="btn btn-default" />
        </div>
    </div>
}