Convert an Enum to a List<object>

Question

First, to avoid the knee-jerk "This is a duplicate" statements: There are plenty of questions on SO about serializing enums. But none (that I have found) deal with enums that have descriptions, or that try to convert an Enum to a specific object. (If you can find one that I missed, then I will accept that this is a duplicate.)

Given an enum that looks something like this:

public enum OptionType
{
    [Description("Option A")]
    OptionA = 1,

    [Description("Option B")]
    OptionB = 2,

    Description("Option C")]
    OptionC= 3,
    }

I would like to convert this into a JSON string that looks like this:

[
    { "Id": "1", "Description": "Option A"},
    { "Id": "2", "Description": "Option B"},
    { "Id": "3", "Description": "Option C"}
]

I have these two classes:

public class EnumList
{
    public List<EnumNameValue> EnumNamesValues { get; set; }
}

public class EnumNameValue
{
    public int Id { get; set; }
    public string Description { get; set; }
}

And I have a calling method that looks like this:

EnumList enumList = EnumSerializer.EnumToJson<OptionType>();

And finally (and this is where I need help):

public static class EnumSerializer
{
    public static EnumList EnumToJson<T>() where T : Enum
    {
        Type enumType = typeof(T);                                 // <--- WORKS!!
        Enum thisEnum1 = (T)Activator.CreateInstance(enumType);    // <--- DOES NOT WORK
        Enum thisEnum2 = (Enum)Activator.CreateInstance(enumType); // <--- DOES NOT WORK

        // If I can get this far, I *THINK* I can figure it out from here
   
    }
}

I already have an Enum extension that gets the Description, so I don't need help with that. The problem I'm having is that both thisEnum1 and thisEnum2 end up having a value of 0

( DistrictType is the real name of the Enum.)

How do I get an actual instance of the enum that I can then loop over?

Answer 1

public static class EnumSerializer
{
    public static EnumList EnumToJson<T>() where T : struct, Enum
    {
        var type = typeof(T);
        var values = Enum.GetValues<T>()
            .Select(x => new EnumNameValue
            {
                Id = (int)(object)x,
                Description = type.GetField(x.ToString())
                    .GetCustomAttribute<DescriptionAttribute>().Description
            });

        return new EnumList { EnumNamesValues = values.ToList() };
    }
}

Working example

Enum.GetValues iterates over the constants declared in your enum.

Of course you can swap out the Description part with your extension method.