List enum values

EnumUtil.cs

private static readonly string unknownEnumId = "unknown";
private static readonly Dictionary<Type, object> enumValuesCache =
    new Dictionary<Type, object>();
    
/// <summary>
/// List all values anotated by XmlEnum
/// </summary>
/// <returns></returns>
public static List<XmlEnumValue<TEnum>> GetEnumValues<TEnum>() {
    var t = typeof(TEnum);
    if (enumValuesCache.ContainsKey(t)) {
        return enumValuesCache[t] as List<XmlEnumValue<TEnum>>;
    }
    else {
        var vals = new List<XmlEnumValue<TEnum>>();
        var fs = t.GetFields();
        var prefix = t.ToString().ToLower() + ".";
        foreach (var f in fs) {
            var attrs = f.GetCustomAttributes(typeof(
                XmlEnumAttribute), false);
            if (attrs != null && attrs.Length > 0) {
                var id = (attrs[0] as XmlEnumAttribute).Name;
                if (id != unknownEnumId) {
                    var val = new XmlEnumValue<TEnum>() {
                        Value = (TEnum)f.GetValue(null),
                        Id = id, Name = GetMessage(prefix + id)
                    };
                    vals.Add(val);
                }
            }
        }
        enumValuesCache.Add(t, vals);
        return vals;
    }
}

/// <summary>
/// Get message
/// </summary>
/// <param name="id">message id</param>
/// <returns></returns>
public static string GetMessage(string id) {
    return i18n.GetMessageValue(id);
}