MVC 4, Checkbox list and me

Question

Morning all.

I can see this has been discussed elsewhere but was wondering if anything had change or things made simpler in MVC 4 for simpletons like me?!

Answer 1

Right ok, I have got it sorted - hurrah! As you can see from the comments, there were a few issues that came up but please find below the complete solution which DOES work :D

Model

 public class CorporateDetails
    {

        public Guid? Id { get; set; }

        [Key]
        public int CorporateDetailId { get; set; }

        public int[] EmsId { get; set; }

        }

    public class EmsType
    {
        [Key]
        public int EmsId { get; set; }
        public string EmsName { get; set; }

        public virtual ICollection EmsTypes { get; set; }
    }

Controller

 public ActionResult Create()
    {
        CorporateDetails corporatedetails = new CorporateDetails();
        ViewBag.EmsId = new MultiSelectList(db.EmsTypes, "EmsId", "EmsName");
        return View(corporatedetails);
    }

Extension (placed in a folder in the root of the project)

 public static MvcHtmlString CheckBoxListFor(this HtmlHelper htmlHelper, Expression> expression, MultiSelectList multiSelectList, object htmlAttributes = null)
    {
        //Derive property name for checkbox name
        MemberExpression body = expression.Body as MemberExpression;
        string propertyName = body.Member.Name;

        //Get currently select values from the ViewData model
        TProperty[] list = expression.Compile().Invoke(htmlHelper.ViewData.Model);

        //Convert selected value list to a List for easy manipulation
        List selectedValues = new List();

        if (list != null)
        {
            selectedValues = new List(list).ConvertAll(delegate(TProperty i) { return i.ToString(); });
        }

        //Create div
        TagBuilder divTag = new TagBuilder("div");
        divTag.MergeAttributes(new RouteValueDictionary(htmlAttributes), true);

        //Add checkboxes
        foreach (SelectListItem item in multiSelectList)
        {
            divTag.InnerHtml += String.Format("
{3}
",
                                                propertyName,
                                                item.Value,
                                                selectedValues.Contains(item.Value) ? "checked=\"checked\"" : "",
                                                item.Text);
        }

        return MvcHtmlString.Create(divTag.ToString());
    }

Extension registered in web config of the Views

View

@model Valpak.Websites.HealthChecker.Models.CorporateDetails
@{
    ViewBag.Title = "Create";
}
Create
@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)

    

        
CorporateDetails

           

           @Html.CheckBoxListFor(model => model.EmsId, (MultiSelectList) ViewBag.EmsId)
          
          
        

            
        
    
}

    @Html.ActionLink("Back to List", "Index")

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

Which gives me a lovely list of check boxes. Hurrah!

Thanks Darin for your help, I've marked this as the answer but +50 for your time and effort.