Enum ToString

Question

My enum consists of the following values:

private enum PublishStatusses{
 NotCompleted,
 Completed,
 Error
};

I want to be able to output these values in a user friendly way though.
In this SO post, there is a lot of code that I can't seem to compile..
I don't need to be able to go from string to value again.
Why is it not compiling at my machine? How can I get such a result?

Answer 1

I use the Description attribute from the System.ComponentModel namespace. Simply decorate the enum and then use this code to retrieve it:

public static string GetDescription<T>(this object enumerationValue)
            where T : struct
        {
            Type type = enumerationValue.GetType();
            if (!type.IsEnum)
            {
                throw new ArgumentException("EnumerationValue must be of Enum type", "enumerationValue");
            }

            //Tries to find a DescriptionAttribute for a potential friendly name
            //for the enum
            MemberInfo[] memberInfo = type.GetMember(enumerationValue.ToString());
            if (memberInfo != null && memberInfo.Length > 0)
            {
                object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);

                if (attrs != null && attrs.Length > 0)
                {
                    //Pull out the description value
                    return ((DescriptionAttribute)attrs[0]).Description;
                }
            }
            //If we have no description attribute, just return the ToString of the enum
            return enumerationValue.ToString();

        }

Answer 2

If you want something completely customizable, try out my solution here:

http://www.kevinwilliampang.com/post/Mapping-Enums-To-Strings-and-Strings-to-Enums-in-NET.aspx

Basically, the post outlines how to attach Description attributes to each of your enums and provides a generic way to map from enum to description.

Answer 3

foreach( PublishStatusses p in Enum.GetValues (typeof(PublishStatusses)) )
{
   Console.WriteLine (p);
}

Answer 4

That other post is Java. You can't put methods in Enums in C#.

just do something like this:

PublishStatusses status = ...
String s = status.ToString();

If you want to use different display values for your enum values, you could use Attributes and Reflection.

Answer 5

The easiest solution here is to use a custom extension method (in .NET 3.5 at least - you can just convert it into a static helper method for earlier framework versions).

public static string ToCustomString(this PublishStatusses value)
{
    switch(value)
    {
        // Return string depending on value.
    }
    return null;
}

I am assuming here that you want to return something other than the actual name of the enum value (which you can get by simply calling ToString).

Answer 6

Maybe I'm missing something, but what's wrong with Enum.GetName?

public string GetName(PublishStatusses value)
{
  return Enum.GetName(typeof(PublishStatusses), value)
}

edit: for user-friendly strings, you need to go through a .resource to get internationalisation/localisation done, and it would arguably be better to use a fixed key based on the enum key than a decorator attribute on the same.

Answer 7

I do this with extension methods:

public enum ErrorLevel
{
  None,
  Low,
  High,
  SoylentGreen
}

public static class ErrorLevelExtensions
{
  public static string ToFriendlyString(this ErrorLevel me)
  {
    switch(me)
    {
      case ErrorLevel.None:
        return "Everything is OK";
      case ErrorLevel.Low:
        return "SNAFU, if you know what I mean.";
      case ErrorLevel.High:
        return "Reaching TARFU levels";
      case ErrorLevel.SoylentGreen:
        return "ITS PEOPLE!!!!";
    }
  }
}

Answer 8

With respect to Ray Booysen, there is a bug in the code: http://stackoverflow.com/questions/479410/enum-tostring/479417#479417

You need to account for multiple attributes on the enum values.

public static string GetDescription<T>(this object enumerationValue)
            where T : struct
    {
        Type type = enumerationValue.GetType();
        if (!type.IsEnum)
        {
            throw new ArgumentException("EnumerationValue must be of Enum type", "enumerationValue");
        }

        //Tries to find a DescriptionAttribute for a potential friendly name
        //for the enum
        MemberInfo[] memberInfo = type.GetMember(enumerationValue.ToString());
        if (memberInfo != null && memberInfo.Length > 0)
        {
            object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);

            if (attrs != null && attrs.Length > 0 && attrs.Where(t => t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault() != null)
            {
                //Pull out the description value
                return ((DescriptionAttribute)attrs.Where(t=>t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault()).Description;
            }
        }
        //If we have no description attribute, just return the ToString of the enum
        return enumerationValue.ToString();