Asp.net mvc 3 编辑模板&x2B；模型未在邮寄时返回

我似乎无法理解这一点，这让我发疯了

本质上，我有一个需要显示的行列表，每行有一个下拉列表

我有一个视图模型：

public class UserMembershipViewModel:BaseViewModel
{
    public List<ProgramMembership> ProgramMembership { get; set; }
}

---

任何帮助都将不胜感激

由于属性名是一个集合，为了更好的可读性，我会将其复数

public class UserMembershipViewModel:BaseViewModel
{
    public List<ProgramMembership> ProgramMemberships { get; set; }
}

---

@戈登：不客气。很高兴我能帮忙：）

@using AcnCS.Model
@model List<AcnCS.Model.ProgramMembership>

@foreach(ProgramMembership membership in Model)
{
    <tr>
        <td>@membership.ProgramName</td>
        <td>
            @if (membership.IsMember)
            {
                <span class="label label-success">@membership.IsMember</span>
            }
            else
            {
                @membership.IsMember
            }
        </td>
        <td>@Html.DropDownListFor(x => membership.PermissionType, membership.PermissionTypes)</td>
    </tr>
}

    [HttpPost]
    public ActionResult Membership(UserMembershipViewModel model)
    {

        // model IS NULL!!

        return View(model);
    }

public class UserMembershipViewModel:BaseViewModel
{
    public List<ProgramMembership> ProgramMemberships { get; set; }
}

@model AcnCS.Model.ProgramMembership
<tr>
    <td>@membership.ProgramName</td>
    <td>
      @if (membership.IsMember)
      {
         <span class="label label-success">@membership.IsMember</span>
      }
      else
      {
         @membership.IsMember
      }
    </td>
    <td>@Html.DropDownListFor(x => membership.PermissionType, membership.PermissionTypes)</td>
</tr>

@Html.EditorFor(m=>m.ProgramMemberships)