Cherian Thomas

Friend | Co-founder of Cucumbertown| Cook | I make beautiful things that keep me up all day & night
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6 July 2008

Enum with attributes

Recently I came across an implementation where enum is converted to string and vice versa (http://blogs.msdn.com/tims/archive/2004/04/02/106310.aspx ). The disadvantage here is that, say you want get the string for something like this “Not available”.

enum Status {
  Not_Available,
  Available_For_Game,
  Available_For_Discussion
}

The string conversion here for the first one would yield Not_Available. This is not desirable in some cases where you don’t want the “_”. A better implementation would be to create attributes to this enum and then extract this.


  public enum Status {
    [Status(Description = "Not Available")]
    Not_Available = 1,
    [Status(Description = "Available For Game")]
    Available_For_Game = 2,
    [Status(Description = "Available For Discussion")]
    Available_For_Discussion = 3,
  }
  public class StatusEnumInfo {
    private static StatusAttribute[] edesc;
    public static String GetDescription(object e)
    {
      System.Reflection.FieldInfo f = e.GetType().GetField(e.ToString());
      StatusEnumInfo.edesc = f.GetCustomAttributes(typeof(StatusAttribute), false) as StatusAttribute[];
      if (StatusEnumInfo.edesc != null && StatusEnumInfo.edesc.Length == 1)
        return StatusEnumInfo.edesc[0].Description;
      else
        return String.Empty;
    }
    public static object GetEnumFromDesc(Type t, string desc)
    {
      Array x = Enum.GetValues(t);
      foreach (object o in x) {
        if (GetDescription(o).Equals(desc)) {
          return o;
        }
      } return String.Empty;
    }
  }
  public class StatusAttribute : Attribute {
    public String Description { get; set; }
  }

  public class Implemenation {
    public void Run()
    {
      Status statusEnum = (Status)StatusEnumInfo.GetEnumFromDesc(typeof(Status), "Not Available");
      String statusString = StatusEnumInfo.GetDescription(Status.Available_For_Discussion);
    }
  }

You are of course free to generalize this. Correct me if this is not a correct implementation.

  • Very nice and correct implementation 

  • Very effectively written information. It will be priceless to anyone who usess it, including myself. Keep up the nice work

  • Zain

    Learned something new today! thanks 🙂