Converting Enums to Key,Value Pairs

Question

How to convert Enum to Key,Value Pairs. I have converted it in C# 3.0 .

 public enum Translation
    {
        English,
        Russian,
        French,
        German
    }

   string[] trans = Enum.GetNames(typeof(Translation));

   var v = trans.Select((value, key) =>
   new { value, key }).ToDictionary(x => x.key + 1, x => x.value);

In C# 1.0 What is the way to do so?

Answer 1

For C# 3.0 if you have an Enum like this:

public enum Translation
{
    English = 1,
    Russian = 2,
    French = 4,
    German = 5
}

don't use this:

string[] trans = Enum.GetNames(typeof(Translation));

var v = trans.Select((value, key) =>
new { value, key }).ToDictionary(x => x.key + 1, x => x.value);

because it will mess up your key (which is an integer).

Instead, use something like this:

var dict = new Dictionary<int, string>();
foreach (var name in Enum.GetNames(typeof(Translation)))
{
    dict.Add((int)Enum.Parse(typeof(Translation), name), name);
}

Answer 2

I didn't read the question carefully, so my code will not work in C# 1.0 as it utilises generics. Best use it with >= C# 4.0 (>= VS2010)

To make life easier, I've created this helper service.

The usage for the service is as follows:

// create an instance of the service (or resolve it using DI)
var svc = new EnumHelperService();

// call the MapEnumToDictionary method (replace TestEnum1 with your enum)
var result = svc.MapEnumToDictionary<TestEnum1>();

The service code is as follows:

/// <summary>
/// This service provides helper methods for enums.
/// </summary>
public interface IEnumHelperService
{
    /// <summary>
    /// Maps the enum to dictionary.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    Dictionary<int, string> MapEnumToDictionary<T>();
}

/// <summary>
/// This service provides helper methods for enums.
/// </summary>
/// <seealso cref="Panviva.Status.Probe.Lib.Services.IEnumHelperService" />
public class EnumHelperService : IEnumHelperService
{
    /// <summary>
    /// Initializes a new instance of the <see cref="EnumHelperService"/> class.
    /// </summary>
    public EnumHelperService()
    {

    }

    /// <summary>
    /// Maps the enum to dictionary.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    /// <exception cref="System.ArgumentException">T must be an enumerated type</exception>
    public Dictionary<int, string> MapEnumToDictionary<T>() 
    {
        // Ensure T is an enumerator
        if (!typeof(T).IsEnum)
        {
            throw new ArgumentException("T must be an enumerator type.");
        }

        // Return Enumertator as a Dictionary
        return Enum.GetValues(typeof(T)).Cast<T>().ToDictionary(i => (int)Convert.ChangeType(i, i.GetType()), t => t.ToString());
    }
}