MVC checkbox comeing back null - asp.net-mvc

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.