MVC Razor RadioButtonList without any preselected values

Question

Im using RadioButtonList to generate my radio buttons, in a MVC Razor project. Here's an example of my code:

@Html.RadioButtonList(n => n.HouseType)

For some reason my radio button lists gets a preselected value. The first checkbox is always checked, which makes my UI kinda confusing.

How do I disable this in a good way?

One way is to loop through the whole page with Jquery and unselect each box. But thats not a pretty work around imho.

EDIT: Here's more info about HouseType, which is a custom enum.

    public enum HouseType
{
    House,
    Apartment,
    Garage
};

and its called upon by using this line

public HouseType HouseType { get; set; }

Answer 1

You could make the HouseType property a nullable type on your view model. For example if it is an enum type:

public HouseTypes? HouseType { get; set; }

or if it is an integer:

public int? HouseType { get; set; }

---

UPDATE:

It seems that you are using the following helper. This helper doesn't support nullable enum values. So adapt it:

public static class RaidioButtonListHelper
{
    /// <summary>
    /// Create a radiobutton list from viewmodel.
    /// </summary>
    public static MvcHtmlString RadioButtonList<TModel, TResult>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TResult>> expression, IEnumerable<SelectListItem> listOfValues = null)
    {
        var typeOfProperty = expression.ReturnType;

        // Added by Darin Dimitrov to support nullable enums
        var underlyingType = Nullable.GetUnderlyingType(typeOfProperty);
        if (underlyingType != null)
        {
            typeOfProperty = underlyingType;
        }
        // End of addition

        if (listOfValues == null && typeOfProperty.IsEnum)
        {
            listOfValues = new SelectList(Enum.GetValues(typeOfProperty));
        }

        var metaData = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);

        // Ctreat table
        TagBuilder tableTag = new TagBuilder("table");
        tableTag.AddCssClass("radio-main");

        // Create tr:s
        var trTagLable = new TagBuilder("tr id=\"" + metaData.PropertyName + "Lables\"");
        var trTagRadio = new TagBuilder("tr id=\"" + metaData.PropertyName + "Radios\"");

        foreach (SelectListItem item in listOfValues)
        {
            var text = item.Text;
            var value = item.Value ?? text;

            // Generate an id to be given to the radio button field 
            var id = string.Format("{0}_{1}", metaData.PropertyName, value);

            // Create the radiobuttons
            var radioTag = htmlHelper.RadioButtonFor(expression, value, new { id = id }).ToHtmlString();

            // Create the label for the radiobuttons.
            var labelTag = htmlHelper.Label(id, HttpUtility.HtmlEncode(text));

            // Add the lables and reaiobuttons to td:s
            var tdTagLable = new TagBuilder("td style=\"padding-left: 10px; text-align: center\"");
            var tdTagRadio = new TagBuilder("td style=\"padding-left: 10px; text-align: center\"");
            tdTagLable.InnerHtml = labelTag.ToString();
            tdTagRadio.InnerHtml = radioTag.ToString();

            // Add tds: to tr:s
            trTagLable.InnerHtml += tdTagLable.ToString();
            trTagRadio.InnerHtml += tdTagRadio.ToString();

        }

        // Add tr:s to table
        tableTag.InnerHtml = trTagLable.ToString() + trTagRadio.ToString();

        //Return the table tag
        return new MvcHtmlString(tableTag.ToString());
    }
}

Now it's gonna work with a nullable enum and it won't select any radio button if the value of the corresponding property is null.