枚举类型工具类

枚举类型与其所对应的含义可通过添加属性的方法进行对应，方便遍历使用

    public enum TrendMode
    {
        [Description("両方")]
        Both,
        [Description("上昇")]
        Up,
        [Description("下降")]
        Down,
    }
    public class EnumHelper
    {
        public static IEnumerable<T> EnumToList<T>()
        {
            Type enumType = typeof(T);

            // Can't use generic type constraints on value types,
            // so have to do check like this
            if (enumType.BaseType != typeof(Enum))
                throw new ArgumentException("T must be of type System.Enum");

            Array enumValArray = Enum.GetValues(enumType);
            List<T> enumValList = new List<T>(enumValArray.Length);

            foreach (int val in enumValArray)
            {
                enumValList.Add((T)Enum.Parse(enumType, val.ToString()));
            }

            return enumValList;
        }

        public static string GetEnumDescription(Enum value)
        {
            FieldInfo fi = value.GetType().GetField(value.ToString());

            DescriptionAttribute[] attributes =
                (DescriptionAttribute[])fi.GetCustomAttributes(
                typeof(DescriptionAttribute),
                false);

            if (attributes != null &&
                attributes.Length > 0)
                return attributes[0].Description;
            else
                return value.ToString();
        }

        public static T GetEnumFromString<T>(string value)
        {
            if (Enum.IsDefined(typeof(T), value))
            {
                return (T)Enum.Parse(typeof(T), value, true);
            }
            else
            {
                string[] enumNames = Enum.GetNames(typeof(T));
                foreach (string enumName in enumNames)
                {
                    object e = Enum.Parse(typeof(T), enumName);
                    if (value == GetEnumDescription((Enum)e))
                    {
                        return (T)e;
                    }
                }
            }
            throw new ArgumentException("The value '" + value
                + "' does not match a valid enum name or description.");
        }
    }