C# EnumHelper枚举帮助类

    /// <summary>
    /// 枚举类型帮助类
    /// </summary>
    public class EnumHelper
    {

        /// <summary>
        /// 获取枚举类型指定字段的特性(Attribute)
        /// </summary>
        /// <typeparam name="T">特性(Attribute)类型</typeparam>
        /// <param name="enumType">枚举类型</param>
        /// <param name="fieldName">字段名称</param>
        /// <returns></returns>
        public static T GetEnumFieldAttribute<T>(Type enumType, string fieldName) where T : Attribute
        {
            if (Enum.IsDefined(enumType, fieldName))
            {
                var field = enumType.GetField(fieldName, BindingFlags.Static | BindingFlags.Public);
                return field.GetCustomAttribute<T>();
            }
            else
            {
                return default(T);
            }
        }

        /// <summary>
        /// 获取枚举的特性
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="enumType"></param>
        /// <returns></returns>
        public static List<T> GetEnumFieldsAttributes<T>(Type enumType) where T : Attribute
        {
            var fields = enumType.GetFields(BindingFlags.Static | BindingFlags.Public);
            return fields.Select(s => s.GetCustomAttribute<T>()).ToList();
        }

        /// <summary>
        /// 根据 DescriptionAttribute 的描述获取枚举项名称
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="description">描述</param>
        /// <returns></returns>
        public static string GetFieldByAttributeDescription<T>(string description) where T : Enum
        {
            var enumType = typeof(T);
            var fields = enumType.GetFields(BindingFlags.Static | BindingFlags.Public);
            var field = fields.Where(s => s.GetCustomAttribute<DescriptionAttribute>()?.Description == description).FirstOrDefault();
            if (field != null)
                return field.Name.ToString();
            else
                return default(T).ToString();
        }

        /// <summary>
        /// 根据 DefaultValueAttribute 的值取枚举项
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="value">值</param>
        /// <returns></returns>
        public static T GetFieldByAttributeDefaultValue<T>(string value) where T : struct
        {
            var enumType = typeof(T);
            var fields = enumType.GetFields(BindingFlags.Static | BindingFlags.Public);
            var field = fields.Where(s => s.GetCustomAttribute<DefaultValueAttribute>()?.Value.ToString().ToLower() == value.ToLower()).FirstOrDefault();
            if (field != null)
            {
                var fieldName = field.Name.ToString();
                T defaultValue = default(T);
                if (Enum.TryParse<T>(fieldName, out defaultValue))
                    return defaultValue;
                else
                    return default(T);
            }
            else
                return default(T);
        }

        /// <summary>
        /// 获取枚举所有项
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public static List<String> GetFields<T>()
        {
            var fields = typeof(T).GetFields(BindingFlags.Static | BindingFlags.Public);
            return fields.Select(s => s.Name).ToList();
        }

    }