Get Constant value and names in a dictionary

ConstantsToKVPair

    public class DoingConstants
    {
        public const string Flying = "F";
        public const string Walking = "W";
        public const string Crawling = "C";
        public const string Scooting = "R";

        static Dictionary<string,string> _asDictionary;
        public static Dictionary<string, string> AsDictionary
        {
            get {
                    if (_asDictionary==null)
                    {
                        _asDictionary = new Dictionary<string, string>();
                        var t = new DoingConstants();
                        foreach (var type in typeof(DoingConstants).GetConsts())
                        {
                            toReturn.Add(type.GetValue(t).ToString(),type.Name);
                        }
                    }
                }
                return _asDictionary;
            }
        }
    }
    
    publich static Helper
    {
        public static List<FieldInfo> GetConsts(this Type type)
        {
            return type.GetFields
            (
                    BindingFlags.Public
                    | BindingFlags.Static 
                    | BindingFlags.FlattenHierarchy
            )
            .Where(fi => fi.IsLiteral && !fi.IsInitOnly)
            .ToList();
        }
   }