控制器动作方法'；表单提交时，s模型参数为空

我在Movie控制器中有一个操作方法ReleaseTheaters，ReleaseTheatres有两个重载，一个是httpGet，它接受Movie Id并执行任务，并返回接受ViewModel对象的ReleaseTherates View，控制器的另一个http操作后方法Release Theaters接受viewModel并将模型数据保存到数据库中。

这是我的视图型号：

 public class MovieReleasingTheatersViewModel
 {
    public MovieReleasingTheatersViewModel()
    {
        AvailableStates = new List<SelectListItem>();
        AvailableCities = new List<SelectListItem>();
        AvailableLocations = new List<SelectListItem>();
        ReleasingTheaters = new List<MovieReleasingTheaterModel>();
    }
    [Display(Name="State")]
    public int? StateId { get; set; }  
    public IList<SelectListItem> AvailableStates { get; set; }
    [Display(Name = "City")]
    public int? CityId { get; set; }
    public IList<SelectListItem> AvailableCities { get; set; }
    public int? LocationId { get; set; }
    public IList<SelectListItem> AvailableLocations { get; set; }
    public IList<MovieReleasingTheaterModel> ReleasingTheaters { get; set; }
}

这是我的控制：

    [HttpGet]
    public ActionResult ReleasingTheaters(int id)
    {
        var model = new MovieReleasingTheatersViewModel();
        model = PrepareMovieReleasingTheaterModel(0, 0, 0, id);
        return View(model);
    }
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult ReleasingTheaters(MovieReleasingTheatersViewModel model)
    {
        // iterate through the model's collection and save or update database
        return View("Index");
    }

这是我的ReleaseingTheaters视图：

 @model Bookmany.Admin.Models.Movie.MovieReleasingTheatersViewModel
 @{
     ViewBag.Title = "Releasing Theaters";
  }
<h3>Releasing Theaters</h3>
@using (Html.BeginForm())
{
 @Html.AntiForgeryToken()
 <table class="table">
    <tr>
        <th>
            @Html.DropDownListFor(model => model.StateId, Model.AvailableStates, "Select  State")
        </th>
        <th>
            @Html.DropDownListFor(model => model.CityId, Model.AvailableCities, "Select City")
        </th>
        <th>
            @Html.DropDownListFor(model => model.LocationId, Model.AvailableLocations, "Select Location")
        </th>
        <th></th>
    </tr>
</table>
<table class="table">
<thead class="t_head">
    <tr>
        <th>
            Theater
        </th>
        <th>
            Date From
        </th>
        <th>
            Date To
        </th>
        <th>
            Release
        </th>
        <th></th>
    </tr>
</thead>
<tbody class="t_body">
    @foreach (var item in Model.ReleasingTheaters)
    {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.TheaterName)
            </td>
            <td>
                @Html.TextBoxFor(modelItem => item.DateFrom, new { id = "DateFrom" })
            </td>
            <td>
                @Html.TextBoxFor(modelItem => item.DateTo, new { id = "DateTo" })
            </td>
            <td>
                @Html.EditorFor(modelItem => item.IsTheaterChecked)
            </td>
        </tr>
    }
</tbody>
</table>
   <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Save" class="btn btn-default" />
        </div>
    </div> 
    }

我的问题：

当我单击提交按钮时，操作方法上的Model对象没有值，viewModel对象的集合属性全部为空我的代码出了什么问题

如何在操作方法上获取模型对象值（集合），以便将这些值保存或更新回数据库

@for (int i = 0; i < Model.ReleasingTheaters.Count; i++)
{
  @Html.TextBoxFor(m => m.ReleasingTheaters[i].DateFrom)
  ....
}

<input type="text" name="ReleasingTheaters[0].DateFrom" id="ReleasingTheaters_0__DateFrom" value="?" >
<input type="text" name="ReleasingTheaters[1].DateFrom" id="ReleasingTheaters_1__DateFrom" value="?" >