C# Enum扩展

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace Automatic_Mouse_Click
{
    internal static class EnumExt
    {
        /// <summary>
        /// 枚举转换为列表;Id表示当前序号;value表示常量值
        /// 支持自定义显示名称.
        ///</summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="item">默认常量</param>
        /// <param name="displayNames">扩展显示名</param>
        /// <returns></returns>
        internal static List<ListItem<int>> ViewList<T>(this T item, params string[] displayNames) where T : Enum
        {
            Type type = typeof(T);
            int i = 0;
            return Enum.GetNames(type).Select(q =>
            {
                var itm = new ListItem<int>()
                {
                    Id = Convert.ToInt32(Enum.Parse(type, q)),
                    Name = q,
                    DisplayName = displayNames.Length > i ? displayNames[i] : q,
                    Value = (int)Enum.Parse(type, q),
                    Type = type.FullName,
                    IsDefault = Enum.GetName(type, item)?.Equals(q) ?? false,
                    Icon = "icon-info"
                };
                ++i;
                return itm;
            }).ToList();
        }

        /// <summary>
        /// 枚举转换为列表;Id表示当前序号;value表示常量值
        /// DisplayName来源于Display属性
        /// 如果未标识Display属性,则取当前默认名称
        ///</summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="item"></param>
        /// <returns></returns>
        internal static List<ListItem<int>> ViewList<T>(this T item) where T : Enum
        {
            Type type = typeof(T);
            return Enum.GetNames(type).Select(q =>
            {
                string dname = type.GetField(q)?.GetCustomAttribute<System.ComponentModel.DataAnnotations.DisplayAttribute>()?.Name;
                dname = !string.IsNullOrEmpty(dname) ? dname : type.GetField(q)?.GetCustomAttribute<System.ComponentModel.DescriptionAttribute>()?.Description;
                var itm = new ListItem<int>()
                {
                    Id = Convert.ToInt32(Enum.Parse(type, q)),
                    Name = q,
                    DisplayName = string.IsNullOrEmpty(dname) ? q : dname,
                    Value = Enum.Parse(type, q),
                    Type = type.FullName,
                    IsDefault = Enum.GetName(type, item)?.Equals(q) ?? false,
                    Icon = "icon-info"
                };
                return itm;
            }).ToList();
        }

        /// <summary>
        /// 通过列表对象,反向获取选中的枚举值
        ///</summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="item"></param>
        /// <returns></returns>
        internal static T EnumValue<T>(this ListItem<int> item) where T : Enum
        {
            return (typeof(T).FullName?.Equals(item.Type) ?? false) ? (T)item.Value : default;
        }

        /// <summary>
        /// 获取枚举值的显示名称(未标识则取枚举名称)
        ///</summary>
        /// <param name="item"></param>
        /// <returns></returns>
        internal static string GetDisplay<T>(this T item) where T : Enum
        {
            Type type = typeof(T);
            string f = Enum.GetName(type, item);
            string d = type.GetField(f)?.GetCustomAttribute<System.ComponentModel.DataAnnotations.DisplayAttribute>()?.Name;
            d = !string.IsNullOrEmpty(d) ? d : type.GetField(f)?.GetCustomAttribute<System.ComponentModel.DescriptionAttribute>()?.Description;
            return d ?? f;
        }


        /// <summary>
        /// 获取枚举值的名称
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="item"></param>
        /// <returns></returns>
        internal static string GetName<T>(this T item) where T : Enum
        {
            return Enum.GetName(typeof(T), item);
        }

        /// <summary>
        /// 通过枚举值获取实际数值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="item"></param>
        /// <returns></returns>
        internal static int ToInt<T>(this T item) where T : Enum
        {
            return Convert.ToInt32(item);
        }

    }
}