using System;

using System.ComponentModel.DataAnnotations;

​

public class Program

{

    public enum MyEnum

    {

        Foo,

        Bar,

        Bat

    }

​

    public class MyClass

    {

        [EnumDataType(typeof (MyEnum))]

        public MyEnum MyProp

        {

            get;

            set;

        }

    }

​

    public static void Main()

    {

        var tmp = new MyClass();

        tmp.MyProp = (MyEnum)(-1);

        Console.WriteLine(tmp.MyProp);

    }

}