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

You can create a generic method which would take Enum and Attribute as generic argument.

For getting any attribute, you can create an extension method like:

public static string AttributeValue(this TEnum value,Func func) where T : Attribute
{
   FieldInfo field = value.GetType().GetField(value.ToString());

   T attribute = Attribute.GetCustomAttribute(field, typeof(T)) as T;

   return attribute == null ? value.ToString() : func(attribute);

}  

and here is the method for converting it to dictionary:

public static Dictionary ToDictionary(this TEnum obj,Func func)
  where TEnum : struct, IComparable, IFormattable, IConvertible
  where TAttribute : Attribute
    {

        return (Enum.GetValues(typeof(TEnum)).OfType()
            .Select(x =>
                new
                {
                    Value = x,
                    Description = x.AttributeValue(func)
                }).ToDictionary(x=>x.Value,x=>x.Description));



    }

You can call it this way:

 var test =  eUserRole.SuperAdmin
                      .ToDictionary(attr=>attr.DisplayName); 

I have used this Enum and Attribute as example:

public class EnumDisplayNameAttribute : Attribute
{
    private string _displayName;
    public string DisplayName
    {
        get { return _displayName; }
        set { _displayName = value; }
    }
}  

public enum eUserRole : int
{
    [EnumDisplayName(DisplayName = "Super Admin")]
    SuperAdmin = 0,
    [EnumDisplayName(DisplayName = "Phoenix Admin")]
    PhoenixAdmin = 1,
    [EnumDisplayName(DisplayName = "Office Admin")]
    OfficeAdmin = 2,
    [EnumDisplayName(DisplayName = "Report User")]
    ReportUser = 3,
    [EnumDisplayName(DisplayName = "Billing User")]
    BillingUser = 4
}

Output: