MVC Razor POST-列表对象始终为null

Question

I've tried several times to get my complex object which contains a list to POST correctly. All the properties except the list object contain values when it posts. I've based my approach on this SO Q&A and this SO Q&A . However, in both case the solution is to use a for loop instead of a foreach loop. I'm using the recommended for loop but still have\\ing an issue. I'm not sure what else could be causing the list to be null when posting. Thanks in advance for your help!

View:

 @model PropertiesAdminSite.Models.UtilityData @{ ViewBag.Title = "CreateNewCycle"; } <h2>New Residence Utilities</h2> @using (Html.BeginForm("Upload", "ImportWater", FormMethod.Post, new { enctype = "multipart/form-data" })) { @Html.AntiForgeryToken() <div class="control-group"> @Html.TextBoxFor(m => m.UploadFile, new { type = "file"}) </div> <div class="control-group"> <input type="submit" class="btn btn-info" value="Upload" /> </div> <div class="col-lg-12 visible-lg"> <br> <span style="color:green">@ViewBag.Message</span> @Html.HiddenFor(model => model.bID) @Html.HiddenFor(model => model.bEntryDate) @Html.HiddenFor(model => model.bPrevDate) @for (int i = 0; i < Model.utilData.Count(); i++) { @Html.HiddenFor(model => model.utilData[i].ResNumber) @Html.HiddenFor(model => model.utilData[i].GrnLower) @Html.HiddenFor(model => model.utilData[i].GrnUpper) @Html.HiddenFor(model => model.utilData[i].prevWaterReading) @Html.HiddenFor(model => model.utilData[i].rID) @Html.HiddenFor(model => model.utilData[i].WaterReading) @Html.HiddenFor(model => model.utilData[i].wDifference) @Html.HiddenFor(model => model.utilData[i].YelLower) @Html.HiddenFor(model => model.utilData[i].YelUpper) } </div> } @using (Html.BeginForm("IndexMulti", "Utilities", FormMethod.Post)) { @Html.AntiForgeryToken() <hr /> @Html.ValidationSummary(true, "", new { @class = "text-danger" }) <div class="row"> <div class="col-lg-12"> <div class="panel panel-default"> <div class="panel-heading"> @Html.LabelFor(model => model.bEntryDate, htmlAttributes: new { @class = "control-label col-md-1" }) @Html.DisplayFor(model => model.bEntryDate) @Html.HiddenFor(model => model.bID) @Html.HiddenFor(model => model.bEntryDate) @Html.HiddenFor(model => model.bPrevDate) </div> <!-- /.panel-heading --> <div class="panel-body"> <div class="dataTable_wrapper"> <!--div id="dataTables-example_wrapper" class="dataTables_wrapper form-inline dt-bootstrap no-footer">--> <div class="row"> <div class="col-sm-12"> <table class="table table-striped table-bordered table-hover dataTable no-footer" id="dataTables-Bills" role="grid" aria-describedby="dataTables-example_info"> <!-- /table headers--> <thead> <tr role="row"> <th>@Html.DisplayNameFor(model => model.utilData.First().ResNumber)</th> <th>@Html.DisplayNameFor(model => model.utilData.First().WaterReading)</th> <th> @Html.DisplayNameFor(model => model.utilData.First().prevWaterReading) &nbsp; @Html.DisplayFor(model => model.bPrevDate) </th> <th>@Html.DisplayNameFor(model => model.utilData.First().wDifference)</th> <th>Actions</th> </tr> </thead> <!-- /table body--> <tbody> @for (int i = 0; i < Model.utilData.Count(); i++) { <tr role="row"> <td> @Html.DisplayFor(modelItem => modelItem.utilData[i].ResNumber) @Html.HiddenFor(model => model.utilData[i].GrnLower) @Html.HiddenFor(model => model.utilData[i].GrnUpper) @Html.HiddenFor(model => model.utilData[i].YelLower) @Html.HiddenFor(model => model.utilData[i].YelUpper) </td> <td> @Html.EditorFor(model => model.utilData[i].WaterReading) </td> <td> <span id="@string.Format("prevWater_{0}",Model.utilData[i].rID)"> @Html.DisplayFor(model => model.utilData[i].prevWaterReading) </span> @Html.HiddenFor(model => model.utilData[i].prevWaterReading) </td> <td> <span id="@string.Format("hdifference_{0}",Model.utilData[i].rID)"> @Html.DisplayFor(model => model.utilData[i].wDifference) </span> @Html.HiddenFor(model => model.utilData[i].prevWaterReading) </td> <td> @Html.ActionLink("View History", "ExportDataIndex", "ExportData", new { rID = Model.utilData[i].rID, bId = Model.bID }, null) &nbsp;| &nbsp; <a href="@Url.Action("ExportToExcel", "ExportData", new { rID = Model.utilData[i].rID, bId = Model.bID })" class="btn btn-success"> <i class="fa fa-file-excel-o" aria-hidden="true" title="Export to Excel"></i> </a>&nbsp;| &nbsp; <a href="@Url.Action("ChartData", "Utilities", new { rID = Model.utilData[i].rID, bId = Model.bID })" class="btn btn-info"> <i class="fa fa-bar-chart" aria-hidden="true" title="Water Usage History"></i> </a> </td> </tr> } </tbody> </table> </div> </div> </div> </div> </div> </div> </div> <div class="form-group"> <div class="col-md-offset-0 col-md-8"> <input type="submit" value="Submit Water Readings and Create Invoices" class="btn btn-primary btn-lg btn-block" /> </div> </div> } 

Model:

public partial class UtilityData
{
    public DateTime bEntryDate { get; set; }
    public string bPrevDate { get; set; }
    public int bID { get; set; }
    //public int residenceCount { get; set; }
    public List<UtilEntry> utilData { get; set; }
    public HttpPostedFileBase UploadFile { get; set; }


}

public partial class UtilEntry
{
    public int rID { get; set; }
    public long? WaterReading { get; set; }
    public int ResNumber { get; set; }
    public long? prevWaterReading { get; set; }
    public decimal wDifference { get; set; }
    public int GrnUpper { get; set; }
    public int GrnLower { get; set; }
    public int YelUpper { get; set; }
    public int YelLower { get; set; }
}

Controller:

[HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult IndexMulti([Bind(Include = "bEntryDate, bPrevDate,bID,uData")] UtilityData uData)
    {
        if (ModelState.IsValid)
        {
            Omitted for clarity
         }

            return RedirectToAction("Create", "TenantAccount", new { id = uData.bID});
        }

Answer 1

Per @Stephen Muecke I had a typo in the IndexMulti Binding:

 public ActionResult IndexMulti([Bind(Include = "bEntryDate, bPrevDate,bID,utilData")] UtilityData uData)

utilData was udata originally.