Drop-down for Enum MVC helper

EnumDropDown.cs

        public static MvcHtmlString DropdownForEnum<TModel>(this HtmlHelper<TModel> helper, Type type,
            string name, string optionLabel, object htmlAttributes)
        {
            if (!type.IsEnum) throw new ArgumentException("type must be that of an enum", "type");

            var dictionary = new Dictionary<string, string>();

            var values = type.GetEnumValues();

            foreach (var val in values)
            {
                dictionary.Add(
                    val.ToString(),
                    type.GetDescriptionForEnum(val)
                    );
            }

            return helper.DropDownList(name, dictionary.ToSelectList(string.Empty), optionLabel, htmlAttributes);
        }

        public static SelectList ToSelectList(this IDictionary<string, string> dictionary, object selectedValue)
        {
            return new SelectList(dictionary, "Key", "Value", selectedValue);
        }

        /// <summary>
        /// Gets the DescriptionAttribute valud of an enum value, if none are found uses the string version of the specified value
        /// </summary>
        public static string GetDescription(this Enum value)
        {
            Type type = value.GetType();

            return GetEnumDescription(value.ToString(), type);
        }

        public static string GetDescriptionForEnum(this Type type, object value)
        {
            return GetEnumDescription(value.ToString(), type);
        }

        private static string GetEnumDescription(string value, Type type)
        {
            MemberInfo[] memberInfo = type.GetMember(value);

            if (memberInfo != null && memberInfo.Length > 0)
            {
                // default to the first member info, it's for the specific enum value
                var info = memberInfo.First().GetCustomAttributes(typeof(DescriptionAttribute), false).FirstOrDefault();

                if (info != null)
                    return ((DescriptionAttribute)info).Description;
            }

            // no description - return the string value of the enum
            return value;
        }