C# explicit initialization for Enum

Question

I have the following statement:

private Enum _statusValue;

What I'd really like to say is:

private Enum _statusValue = 0;

even though I know it's redundant. It's just that I like to explicitly specify the initialization.

But that is not allowed.

Is there some simple way of specifying the initialization on this kind of declaration?

EDIT - Let me try again.

Here is a contrived / simplified example of what I'm doing.

using System;

namespace EnumTesting
{
   public enum EFixedPhoneUsability
   {
      UnknownValue,       // Should not occur?
      IsUsable,           // User is near the telephone
      NotUsable,          // User not near the telephone
      BeingUsed,          // Busy
      DoNotDisturb,       // This is phone physical state, not user attitude
      CallsForwarded      // This is phone physical state
   }

   public enum EMobilePhoneConnectivity
   {
      UnknownValue,       // Should not occur?
      OnNetIdle,          // I.e., usable
      OnNetBusy,          // Being used
      NoConnection        // Turned off, in elevator or tunnel or far from civilization
   }

   public class Program
   {
      public Enum StatusValue;

      static void Main(string[] args)
      {
         Program p = new Program();

         p.StatusValue = EMobilePhoneConnectivity.NoConnection;

         int i = (int) (EMobilePhoneConnectivity) p.StatusValue;

         p.StatusValue = EFixedPhoneUsability.DoNotDisturb;

         i = (int) (EFixedPhoneUsability) p.StatusValue;
      }
   }
}

So my question is, can I add a generic initializer to this statement?

      public Enum StatusValue;

SECOND EDIT:

Never mind, I have discovered the error of my ways, thanks to this posting:

How to convert from System.Enum to base integer?

The key phrase, which made me realize what I was doing wrong, is this: "enumerations are value types (and internally represented only by integer constants) while System.Enum is a reference type".

So I do not want to say this:

private Enum _statusValue = 0;

I want to say this, which is perfectly valid:

private Enum _statusValue = null;

Thank you to those who tried to help.

`private Enum _statusValue` is a type definition. You can't initialize a type definition. — Joel Etherton, Dec 10 '10 at 16:29
I don't think that is correct. Isn't it a field definition? It works like a field definition - I can assign a value to it using some other enum, and retrieve the value from it using a cast. — RenniePet, Dec 10 '10 at 17:05
@RenniePet: you can answer your own question, and then accept it. That way this question gets closed. — dvdvorle, Jul 11 '11 at 06:14

score 10 · Answer 1 · answered Dec 10 '10 at 16:29

10

You could always declare your Enum slightly differently and add a default state (which is actually suggested by Microsoft):

public enum MyEnum
{
    Default = 0,
    One = 1, 
    Two = 2
}

Or simply (automatic numbering starts at 0):

public enum MyEnum
{
    Default,
    One,
    Two
}

Which would allow you to do the following:

private MyEnum _enum = MyEnum.Default;

answered Dec 10 '10 at 16:29

Justin Niessner

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Thanks for your suggestion, but what I'm hoping to do is to avoid introducing a new enum MyEnum whose only purpose would be to provide syntactic sugar for not being able to use a literal zero. I've edited and expanded my question, and I'd appreciate it if you'd take a look at it again. Thanks. – RenniePet Dec 11 '10 at 06:58

score 2 · Accepted Answer · answered Jul 11 '11 at 10:57

My question was basically in error. I had mistakenly thought Enum (like enums) was a value type, but it is actually a reference type.

So I do not want to say this:

private Enum _statusValue = 0;

I want to say this, which is perfectly valid:

private Enum _statusValue = null;

Thank you to those who tried to help.

C# explicit initialization for Enum

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