Question

I have a checkbox, but the form is being submitted the value ticked are not being submited…

Html:

@foreach (var radiobutton in Model.InterestedIn)
           {
             <span >  @Html.CheckBox("selected", radiobutton)
               <label>@radiobutton</label></span>
               <br />
           } 

Model:

[Display(Name = "Would you be interested in receiving *")]
        public IList<string> InterestedIn { get; set; }

Controller:

IList<string> lists = new List<string>();
            lists.Insert(0, "Latest News");
            lists.Insert(1, "Special Offers");
            lists.Insert(1, "New Products");
            model.InterestedIn = lists;

PostMethod:

[HttpPost]
        public ActionResult Index(Competition model)
        {
            if (ModelState.IsValid)
            {

Answer 1

I don’t that your code will compile at all. The CheckBox helper expects a boolean as second argument whereas you are passing it a string.

Try like this:

@model MyViewModel

@using (Html.BeginForm())
{
    foreach (var value in Model.InterestedIn)
    {
        <span>
            <input type="checkbox" name="interestedin" value="@Html.AttributeEncode(value)" />
            <label>@value</label>
        </span>
        <br />
    } 
    <button type="submit">OK</button>
}

This assumes that you have the following view model:

public class MyViewModel
{
    [Display(Name = "Would you be interested in receiving *")]
    public IList<string> InterestedIn { get; set; }
}

and the following controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        IList<string> lists = new List<string>();
        lists.Insert(0, "Latest News");
        lists.Insert(1, "Special Offers");
        lists.Insert(1, "New Products");
        var model = new MyViewModel();
        model.InterestedIn = lists;
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(MyViewModel model)
    {
        return View(model);
    }
}

If you want to use the CheckBox or even better the CheckBoxFor helper you will have to adapt your view model so that it no longer has an IList<string> property but an IList<CheckBoxItemViewModel> property where CheckBoxItemViewModel is another view model that will contain the label and a boolean property indicating whether this value has been selected or not.