WPF EnumItemsSource

EnumItemsSource.cs

    /// <summary>
    /// Allows us to use enum values as a data source; e.g. for providing as an ItemsSource
    /// on a combo box control for user selection.
    /// </summary>
    public class EnumItemsSource : Collection<String>, IValueConverter
    {
        Type _type;
        IDictionary<Object, Object> _valueToNameMap;
        IDictionary<Object, Object> _nameToValueMap;

        public Type Type
        {
            get { return _type; }
            set
            {
                if (!value.IsEnum)
// ReSharper disable LocalizableElement
                    throw new ArgumentException("Type is not an enum.", "value");
// ReSharper restore LocalizableElement
                _type = value;
                Initialize();
            }
        }

        public Object Convert(Object value, Type targetType, Object parameter, CultureInfo culture)
        {
            return _valueToNameMap != null ? _valueToNameMap[value] : null;
        }

        public Object ConvertBack(Object value, Type targetType, Object parameter, CultureInfo culture)
        {
            if (value == null) return null;
            return _nameToValueMap != null ? _nameToValueMap[value] : null;
        }

        void Initialize()
        {
            _valueToNameMap = _type
              .GetFields(BindingFlags.Static | BindingFlags.Public)
              .ToDictionary(fi => fi.GetValue(null), GetDescription);
            _nameToValueMap = _valueToNameMap
              .ToDictionary(kvp => kvp.Value, kvp => kvp.Key);
            Clear();
            foreach (var name in _nameToValueMap.Keys)
                Add(name as string);
        }

        static Object GetDescription(FieldInfo fieldInfo)
        {
            var descriptionAttribute =
              (DescriptionAttribute)Attribute.GetCustomAttribute(fieldInfo, typeof(DescriptionAttribute));
            return descriptionAttribute != null ? descriptionAttribute.Description : fieldInfo.Name;
        }

    }