Enum Dropdown List in Asp.Net MVC

public static partial class MyEnumDropDownList
{
    #region Enum DropDown

    public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper,
        Expression<Func<TModel, TEnum>> expression)
    {
        return EnumDropDownListFor(htmlHelper, expression, null);
    }

    public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper,
        Expression<Func<TModel, TEnum>> expression, string optionLabel)
    {
        return EnumDropDownListFor(htmlHelper, expression, optionLabel, null);
    }

    public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper,
        Expression<Func<TModel, TEnum>> expression, string optionLabel, object htmlAttributes)
    {
        ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
        Type enumType = GetNonNullableModelType(metadata);
        IEnumerable<TEnum> values = Enum.GetValues(enumType).Cast<TEnum>();

        IEnumerable<SelectListItem> items = from value in values
                                            select new SelectListItem
                                            {
                                                Text = GetEnumDescription(value),
                                                Value = value.ToString(),
                                                Selected = value.Equals(metadata.Model)
                                            };

        // If the enum is nullable, add an 'empty' item to the collection
        if (metadata.IsNullableValueType)
            items = SingleEmptyItem.Concat(items);

        return htmlHelper.DropDownListFor(expression, items, optionLabel, htmlAttributes);
    }

    public static MvcHtmlString EnumDropDownList<TEnum>(this HtmlHelper htmlHelper, string name, TEnum selectedValue)
    {
        return EnumDropDownList(htmlHelper, name, selectedValue, null);
    }

    public static MvcHtmlString EnumDropDownList<TEnum>(this HtmlHelper htmlHelper, string name, TEnum selectedValue, object htmlAttributes)
    {
        IEnumerable<TEnum> values = Enum.GetValues(typeof(TEnum))
            .Cast<TEnum>();

        IEnumerable<SelectListItem> items = from value in values
                                            select new SelectListItem
                                            {
                                                Text = value.ToString(),
                                                Value = value.ToString(),
                                                Selected = (value.Equals(selectedValue))
                                            };

        return htmlHelper.DropDownList(name, items, htmlAttributes);
    }

    #endregion
}