EnumHelper.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
 
namespace be.gaudry.model.enums
{
    /// <summary>
    /// Provides a static utility object of methods and properties to interact
    /// with enumerated types.
    /// Source : http://www.codeproject.com/useritems/enumdatabinding.asp
    /// 
    /// public enum SimpleEnum
    /// {
    ///    [EnumDescription("Today")]
    ///    Today,
    /// ...
    /// 
    /// ComboBox combo = new ComboBox();
    /// combo.DataSource = EnumHelper.ToList(typeof(SimpleEnum));
    /// combo.DisplayMember = "Value";
    /// combo.ValueMember = "Key";
    /// </summary>
    public static class EnumHelper
    {
        /// <summary>
        /// Gets the <see cref="DescriptionAttribute" /> of an <see cref="Enum" />
        /// type value.
        /// </summary>
        /// <param name="value">The <see cref="Enum" /> type value.</param>
        /// <returns>A string containing the text of the
        /// <see cref="DescriptionAttribute"/>.</returns>
        public static string GetDescription(Enum value)
        {
            if (value == null)
            {
                throw new ArgumentNullException("value");
            }
 
            string description = value.ToString();
            FieldInfo fieldInfo = value.GetType().GetField(description);
            EnumDescriptionAttribute[] properties = null;
            try
            {
                properties = (EnumDescriptionAttribute[])fieldInfo.GetCustomAttributes(
                   typeof(EnumDescriptionAttribute),
                   false
                   );
            }
            catch
            {
 
            }
            if (properties != null && properties.Length > 0)
            {
                description = properties[0].Description;
            }
            return description;
        }
 
        /// <summary>
        /// Converts the <see cref="Enum" /> type to an <see cref="IList" /> 
        /// compatible object.
        /// </summary>
        /// <param name="type">The <see cref="Enum"/> type.</param>
        /// <returns>An <see cref="IList"/> containing the enumerated
        /// type value and description.</returns>
        public static IList ToList(Type type)
        {
            if (type == null)
            {
                throw new ArgumentNullException("type");
            }
 
            ArrayList list = new ArrayList();
            Array enumValues = Enum.GetValues(type);
 
            foreach (Enum value in enumValues)
            {
                list.Add(getKeyValuePair(value));
            }
 
            return list;
        }
 
        public static KeyValuePair<Enum, string> getKeyValuePair(Enum value)
        {
            if (value == null)
            {
                throw new ArgumentNullException("value");
            }
            return new KeyValuePair<Enum, string>(value, GetDescription(value));
        }
 
        public static Dictionary<Enum, string> getDictionary(Type type)
        {
            Dictionary<Enum, string> dico = new Dictionary<Enum, string>();
            if (type == null)
            {
                return dico;
            }
 
            Array enumValues = Enum.GetValues(type);
 
            foreach (Enum value in enumValues)
            {
                dico.Add(value, GetDescription(value));
            }
 
            return dico;
        }
 
        public static Enum getEnum(Object keyValuePair)
        {
            if (keyValuePair == null) return null;
            try
            {
                KeyValuePair<Enum, string> kvp = (KeyValuePair<Enum, string>)keyValuePair;
                return kvp.Key;
            }
            catch (InvalidCastException)
            {
                return null;
            }
        }
    }
}