How can I make an “abstract” enum in a .NET class library?

Question

I\'m making a server library in which the packet association is done by enum.

public enum ServerOperationCode : byte
{
    LoginResponse = 0x00,
    Selectio         


        

Answer 1

I like to use static instances on my classes when I need to do this. It allows you to have some default values but also lets it be extensible through the usual means of inheritance and interface implementations:

    public abstract class OperationCode
    {
        public byte Code { get; private set; }
        public OperationCode(byte code)
        {
            Code = code;
        }
    }

    public class ServerOperationCode : OperationCode
    {
        public static ServerOperationCode LoginResponse = new ServerOperationCode(0x00);
        public static ServerOperationCode SelectionResponse = new ServerOperationCode(0x01);
        public static ServerOperationCode BlahBlahResponse = new ServerOperationCode(0x02);

        public ServerOperationCode(byte code) : base(code) { }
    }

    public class ClientOperationCode : OperationCode
    {
        public static ClientOperationCode LoginRequest = new ClientOperationCode(0x00);
        public static ClientOperationCode SelectionRequest = new ClientOperationCode(0x01);
        public static ClientOperationCode BlahBlahRequest = new ClientOperationCode(0x02);

        public ClientOperationCode(byte code) : base(code) { }
    }

assuming packet.OperationCode return a byte, you will likely have to implement an == operator for byte. put this code into your abstract OperationCode class.

public static bool operator ==(OperationCode a, OperationCode b)
{
  return a.Code == b.Code;
}

public static bool operator !=(OperationCode a, OperationCode b)
{
  return !(a == b);
}

this will allow you to have the same check as you showed:

if (packet.OperationCode == ClientOperationCode.LoginRequest)