具有部分视图的MVC 4模型绑定

Question

@using (Html.BeginForm("PrintDoorSigns", "TimeTable", FormMethod.Post, new { id = "printDoorSigns" }))
{
    <input type="hidden" id="doorSignDate" name="SelectedDate" />
    <h3>Door Signs</h3>
    <fieldset class="float-left">
        <legend>Date</legend>
        <div id="signsDate"></div>
    </fieldset>
    <div id="doorSignsRoomList" class="float-left">
        @{Html.RenderAction("DoorSignsForm", new { date = DateTime.Now });}
    </div>
    <div>
    <fieldset>
        <legend>Options</legend>
        <button id="SelectAllRooms">Select All</button>
        <button id="RemoveAllRooms">Remove All</button>
    </fieldset>
    </div>
}

I have this form which renders this partial view:

@model WebUI.ViewModels.CalendarVM.DoorSignsFormVM

<fieldset>
    <legend>Rooms</legend>
    @{ var htmlListInfo = new HtmlListInfo(HtmlTag.vertical_columns, 3, null, TextLayout.Default, TemplateIsUsed.No);
        if (Model.Rooms.Count() > 0)
        {
            <div id="roomsWithBookings" class="CheckBoxList float-left">
                @Html.CheckBoxList("SelectedRooms", model => model.Rooms, entity => entity.Value, entity => entity.Text, model => model.SelectedRooms, htmlListInfo)
            </div>
        }
    }   
</fieldset>

Controller action:

public ActionResult PrintDoorSigns(DateTime SelectedDate, DoorSignsFormVM Model)

when I submit the form, the hidden input "SelectedDate" gets passed back fine and the Model variable which contains two IEnumerable variables isn't null. One of the lists is null which I expect, as it shouldn't be passed back and the SelectedRooms variable which I expect to be populated is a new list with count 0.

I assume the binding is just wrong on this property but I don't understand why, any pointers? Thanks

EDIT:

    public PartialViewResult DoorSignsForm(DateTime date)
    {
        var userID = _bookingService.GetCurrentUser(User.Identity.Name);

        var model = new DoorSignsFormVM();
        model.Rooms = _sharedService.GetRoomsWithBookings(date, userID.FirstOrDefault().DefSite);

        return PartialView("_DoorSigns", model);
    }

Here is the doorsignsform action that gets rendered in the form.

Answer 1

As you say, ASP.NET MVC is not recognizing the checkbox values as being part of the DoorSignsFormVM view model.

Given that your SelectedRooms property is a collection of SelectListItem s, MVC is not recognizing how to bind the string values from the checkboxes to this property.

Try adding another property called SelectedRoomValues of type string[] to your viewmodel and change your checkbox code to

@Html.CheckBoxListFor(model => model.SelectedRoomValues, model => model.Rooms, entity => entity.Value, entity => entity.Text, model => model.SelectedRooms, htmlListInfo)

MVC will then know how to bind to this new property, which will be populated with the SelectListItem.Value values.