Custom attributes & Enum 2

Display values of custom attribute in Drop Down

Is there any advantage of adding custom attribute in Enum?

I want to bind some Cartoon Character names to drop down box; these values keep as Enum in my project. As we all know Enums doesn’t support spaces and special characters. So… use custom attribute

Method to get Enum as a collection

        public static IEnumerable<CartoonCharacters> GetCommenttype()
        {
            yield return CartoonCharacters.TinTin;
            yield return CartoonCharacters.SpongeBob;
            yield return CartoonCharacters.SpiderMan;
            yield return CartoonCharacters.BugsBunny;
            yield return CartoonCharacters.TomAndJerry;
            yield return CartoonCharacters.DonaldDuck;
        }

If you think yield keyword is new to you, I found two great articles

Using C# Yield for Readability and Performance
Behind the scenes of the C# yield keyword

Method to bind data

        public static Dictionary<CartoonCharacters, string> GetCartoonCharacters()
        {
            var list = new Dictionary<CartoonCharacters, string>();

            foreach (CartoonCharacters item in GetCommenttype())
            {
                list.Add(item, GetDescription(item));
            }
           
            return list;
        }

Don’t forget to bind data collection with drop down

 ddlCartoonCharacters.DataSource = GetCartoonCharacters();
 ddlCartoonCharacters.DataTextField = "value";
 ddlCartoonCharacters.DataValueField = "key";
 ddlCartoonCharacters.DataBind();

Final look

Custom attributes & Enum

Formal introduction to Enum: provides an efficient way to define a set of named integral constants that may be assigned to a variable.

As we use enums in our day today life, we may need small improvements and additional things integrated with enums.

This is my Enum (without custom attribute)

public enum CartoonCharacters
{
    TinTin = 1,
    SpongeBob = 2,
    SpiderMan = 3,
    BugsBunny = 4,
    TomAndJerry = 5,
    DonaldDuck = 6
}

I’m going to integrate descriptive text (some extra values) with my CartoonCharacters enum.

Enum with Description

public enum CartoonCharacters
{
    [Description("Tin Tin")]
    TinTin = 1,
 
    [Description("Sponge Bob")]
    SpongeBob = 2,
 
    [Description("Spider Man")]
    SpiderMan = 3,
 
    [Description("Bugs Bunny")]
    BugsBunny = 4,
 
    [Description("Tom And Jerry")]
    TomAndJerry = 5,
 
    [Description("Donald Duck")]
    DonaldDuck = 6
}
 
public class Description : Attribute
   {
       public string Text;
      
       public Description(string text)
       {
           Text = text;
       }
   }

  Method to read the description

    public static string GetDescription(Enum en)
    {
        Type type = en.GetType();
        MemberInfo[] memInfo = type.GetMember(en.ToString());

        if (memInfo != null && memInfo.Length > 0)
        {
            object[] attrs = memInfo[0].GetCustomAttributes(typeof(Description), false);

            if (attrs != null && attrs.Length > 0)
                return ((Description)attrs[0]).Text;
        }
        return en.ToString();
    }