List not passed to MVC controller after checkbox [duplicate]

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• Post an HTML Table to ADO.NET DataTable 2 answers

I have a list that I would like to utilize checkboxes to select different elements. In my view, the information in passed in correctly, and I get the checkboxes, but when it is saved, the list is empty. I could use some help.

public struct SelectedCategories
    {
    public int categoryID;
    public string PubNum;
    public string category;
    public bool selected;
}
public class CategoryViewModel
{
    public List<SelectedCategories> current_categories_list { get; set; }
}

My controller

    public class CategoryController : Controller
{
    // GET: Category
    public ActionResult Index()
    {
        List<SelectedCategories> CategoryList = new List<SelectedCategories>();
        CategoryList.Add(new SelectedCategories { categoryID = 1, PubNum = "one", selected = false, category = "first" });
        CategoryList.Add(new SelectedCategories { categoryID = 2, PubNum = "two", selected = false, category = "second" });
        CategoryList.Add(new SelectedCategories { categoryID = 3, PubNum = "three", selected = false, category = "third" });

        var viewModel = new CategoryViewModel()
        {
            current_categories_list = CategoryList
        };
        return View(viewModel);
    }
    [HttpPost]
    public ActionResult SaveCategories(CategoryViewModel viewModel)
    {
        return Json(new { Result = "Save Failed " });
    }

}

}

My view

@using (Ajax.BeginForm("SaveCategories", "Category", new AjaxOptions {HttpMethod = "POST", OnSuccess = "FormSubmitSuccess", OnFailure = "FormSubmitFailure" }))
{
<h3> Categories</h3>
    <div id="table-scroll">
        <table class="table-striped">
            <tbody>
                @foreach (var item in Model.current_categories_list)
                {
                    <tr>
                        <td>@Html.DisplayFor(m => item.category)</td>
                        <td>@Html.CheckBoxFor(m => item.selected)</td>
                    </tr>
                }
            </tbody>
        </table>
    </div>

<input id="submitform" type="submit" value="Save Data" style="width: 100px" class="btn btn-success" />
}

In the "save Failed" section, it shows a null value for the list.