How to Create Two level enum

Question

Sorry if the question's title is confusing,but i don't know how to ask it. what is really want is to have read-only data that will never change.

currently i have two enums MeterType and SubMeterType

public enum MeterType
{
  Water = 1001,
  Electricity = 1004,
  Gas = 1007
}

and

public enum SubMeterType
{
  DrinkingWater = 1002,
  UsageWater = 1003,
  SubsidiseGas = 1008,
  NonSusbsidisedGas = 1009
} 

Now i would like to use these as follows

To get the MeterType

string meterType = MeterType.Water.ToString("d");

and to get the SubMeterType, is it possible to have something like

string subMeterType = MeterType.Water.DrinkingWater("d");

Shall go for another approach using classes with readonly properties ? or modify these enums to suit my requirement.

Answer 1

Instead of using enums you might use constant integers in nested classes:

public static class MeterType
{
    public const int Water = 1001;
    public const int Electricity = 1004;
    public const int Gas = 1007;

    public static class Waters
    {
        public const int DrinkingWater = 1002;
        public const int UsageWater = 1003;
    }

    public static class Gases
    {
        public const int SubsidiseGas = 1008;
        public const int NonSusbsidisedGas = 1009;
    }
}