Enum to Dictionary in C#

Question

I have searched this online, but I can\'t find the answer I am looking for.

Basically I have the following enum:

public enum typFoo : int
{
   itemA         


        

Answer 1

You can enumerate over the enum descriptors:

Dictionary<int, string> enumDictionary = new Dictionary<int, string>();

foreach(var name in Enum.GetNames(typeof(typFoo))
{
    enumDictionary.Add((int)((typFoo)Enum.Parse(typeof(typFoo)), name), name);
}

That should put the value of each item and the name into your dictionary.

Answer 2

Adapting Ani's answer so that it can be used as a generic method (thanks, toddmo):

public static Dictionary<int, string> EnumDictionary<T>()
{
    if (!typeof(T).IsEnum)
        throw new ArgumentException("Type must be an enum");
    return Enum.GetValues(typeof(T))
        .Cast<T>()
        .ToDictionary(t => (int)(object)t, t => t.ToString());
}

Answer 3

Using reflection:

Dictionary<int,string> mydic = new Dictionary<int,string>();

foreach (FieldInfo fi in typeof(typFoo).GetFields(BindingFlags.Public | BindingFlags.Static))
{
    mydic.Add(fi.GetRawConstantValue(), fi.Name);
}

Answer 4

Another extension method that builds on Arithmomaniac's example:

    /// <summary>
    /// Returns a Dictionary&lt;int, string&gt; of the parent enumeration. Note that the extension method must
    /// be called with one of the enumeration values, it does not matter which one is used.
    /// Sample call: var myDictionary = StringComparison.Ordinal.ToDictionary().
    /// </summary>
    /// <param name="enumValue">An enumeration value (e.g. StringComparison.Ordianal).</param>
    /// <returns>Dictionary with Key = enumeration numbers and Value = associated text.</returns>
    public static Dictionary<int, string> ToDictionary(this Enum enumValue)
    {
        var enumType = enumValue.GetType();
        return Enum.GetValues(enumType)
            .Cast<Enum>()
            .ToDictionary(t => (int)(object)t, t => t.ToString());
    }

Answer 5

• Extension method
• Conventional naming
• One line
• C# 7 return syntax (but you can use brackets in those old legacy versions of C#)
• Throws an ArgumentException if the type is not System.Enum, thanks to Enum.GetValues
• IntelliSense will be limited to structs (no enum constraint is available yet)
• Allows you to use enum to index into the dictionary, if desired.

public static Dictionary<T, string> ToDictionary<T>() where T : struct
  => Enum.GetValues(typeof(T)).Cast<T>().ToDictionary(e => e, e => e.ToString());

Answer 6

See: How do I enumerate an enum in C#?

foreach( typFoo foo in Enum.GetValues(typeof(typFoo)) )
{
    mydic.Add((int)foo, foo.ToString());
}