Enum to list as an extension?

Question

I have various enums that I use as sources for dropdown lists, In order to provide for a user-friendly description, I added a Description attribute to each enum, an

Answer 1

I have this extension method in my stack and use it for the same thing all the time.

public static string Description(this Enum @enum)
{
    try
    {
        var @string = @enum.ToString();

        var attribute =
            @enum.GetType()
                 .GetField(@string)
                 .GetCustomAttribute(false);

        return attribute != null ? attribute.Description : @string;
    }
    catch // Log nothing, just return an empty string
    {
        return string.Empty;
    }
}

Example usage:

MyEnum.Value.Description(); // The value from within the description attr.

Additionally, you can use this one to get a IDictionary for binding purposes.

public static IDictionary ToDictionary(this Type type)
{
    if (!type.IsEnum)
    {
        throw new InvalidCastException("'enumValue' is not an Enumeration!");
    }

    var names = Enum.GetNames(type);
    var values = Enum.GetValues(type);

    return Enumerable.Range(0, names.Length)
                     .Select(index => new
                     {
                         Key = names[index],
                         Value = ((Enum)values.GetValue(index)).Description()
                     })
                     .ToDictionary(k => k.Key, k => k.Value);
}

Use it like so:

var dictionary = typeof(MyEnum).ToDictionary();

Update

Here is a working .NET Fiddle.

public static Dictionary ToDictionary(this Type type)
    where TEnum : struct, IComparable, IFormattable, IConvertible
{
    return Enum.GetValues(type)
               .OfType()
               .ToDictionary(value => value, value => value.Description());
}

Then use it like this:

public enum Test
{
    [Description("A test enum value for 'Foo'")]
    Foo,
    [Description("A test enum value for 'Bar'")]
    Bar
}

typeof(Test).ToDictionary()