Adding constructor (or function) to enum

Question

I am not sure if a constructor is exactly what I am looking for but if I explain what I am trying to do hopefully someone can tell me if I am trying to do is a silly idea or whether there are ways to do it.

So I have an enum:

public enum MessageType
{
    Normal, 
    Error, 
    Chat, 
    Groupchat, 
    Headline
}

This enum is basically a wrapper for the jabber.net MessageType. So I want to create my enum from this. So at the moment I have a function like this:

private MessageType ConvertMessageType(JabberMessageType jabberType)
{
    MessageType type = MessageType.Error;

    switch (jabberType)
    {
        case JabberMessageType.normal:
            type = MessageType.Normal;
            break;

        //etc
    }

    return type;
}

So I have to use enum MessageType type = ConvertMessageType(JabberMessageType.groupchat);

What I would like though is to be able to do something like:

enum MessageType type = MessageType(JabberMessageType.groupchat);
// or 
enum MessageType type = MessageType.FromJabberJid(JabberMessageType.groupchat);

So that the conversion belongs with the enum rather than being a method outtside of.

Answer 1

Why not create an extension method to do this for you?

public static class ExtensionMethods
{
    public static MessageType ConvertMessageType(this JabberMessageType jabberType)
    {
        switch(jabberType)
        {
            case JabberMessageType.normal:
                return MessageType.Normal;
            // Add rest of types here.
            default:
                return MessageType.Error;
        }
    }
}

Example usage:

var type = JabberMessageType.normal; // JabberMessageType
var messageType = type.ConvertMessageType(); // Converted to your custom MessageType