EnumUtil

Posted 2020-08-14 ChineseMoonGod

EnumUtil.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Reflection;

namespace EnumExtensions
{
    /// <summary>
    /// 枚举实用操作
    /// </summary>
    public static class EnumUtil
    {
        /// <summary>
        /// 把枚举转换为键值对集合
        /// </summary>
        /// <param name="enumType">枚举类型</param>
        /// <param name="getText">以Enum为参数类型，String为返回类型的委托</param>
        /// <returns>以枚举值为key，枚举文本为value的键值对集合</returns>
        public static Dictionary<Int32, String> EnumToDictionary(Type enumType, Func<Enum, String> getText)
        {
            if (!enumType.IsEnum)
            {
                throw new ArgumentException("传入的参数必须是枚举类型！", "enumType");
            }
            Dictionary<Int32, String> enumDic = new Dictionary<int, string>();
            Array enumValues = Enum.GetValues(enumType);
            foreach (Enum enumValue in enumValues)
            {
                Int32 key = Convert.ToInt32(enumValue);
                String value = getText(enumValue);
                enumDic.Add(key, value);
            }
            return enumDic;
        }

        /// <summary>
        /// 在指定枚举中检索具有指定值的描述信息
        /// </summary>
        /// <param name="enumType">枚举类型</param>
        /// <param name="value">特定枚举常数的值（根据其基础类型）</param>
        /// <param name="nameInstead">当枚举值没有定义DescriptionAttribute，是否使用枚举名代替，默认是使用</param>
        /// <returns>enumType的枚举常数的描述信息，如果没有找到这样的枚举常数，则为null。</returns>
        public static String GetDescription(Type enumType, object value, Boolean nameInstead = true)
        {
            Enum e = (Enum)Enum.ToObject(enumType, value);
            return e == null ? null : e.GetDescription(nameInstead);
        }

        /// <summary>
        /// 扩展方法，获得枚举的Description
        /// </summary>
        /// <param name="value">枚举值</param>
        /// <param name="nameInstead">当枚举值没有定义DescriptionAttribute，是否使用枚举名代替，默认是使用</param>
        /// <returns>枚举的Description</returns>
        public static string GetDescription(this Enum value, Boolean nameInstead = true)
        {
            Type type = value.GetType();
            string name = Enum.GetName(type, value);
            if (name == null)
            {
                return null;
            }

            FieldInfo field = type.GetField(name);
            DescriptionAttribute attribute = Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute)) as DescriptionAttribute;

            if (attribute == null&&nameInstead == true)
            {
                return name;
            }
            return attribute == null ? null : attribute.Description;
        }
    }
}

调用方式Program.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;

namespace EnumExtensions
{
    public enum Season
    {
        [Description("春 天")]
        Spring = 1,
        [Description("夏 天")]
        Summer = 2,
        //[Description("秋 天")]
        Autumn = 3,
        [Description("冬 天")]
        Winter = 4
    }
    class Program
    {
        static void Main(string[] args)
        {
            Season spring = Season.Spring;
            //打印枚举名
            Console.WriteLine(spring.ToString());
            //打印枚举说明
            Console.WriteLine(spring.GetDescription());

            //枚举转换为键值对集合
            Dictionary<Int32, String> dic = EnumUtil.EnumToDictionary(typeof(Season), e => e.GetDescription());
            PrintDic(dic);

            dic = EnumUtil.EnumToDictionary(typeof(Season), e => e.GetDescription(false));
            PrintDic(dic);

            dic = EnumUtil.EnumToDictionary(typeof(Season), e => e.ToString());
            PrintDic(dic);

            dic = EnumUtil.EnumToDictionary(typeof(Season), e => Enum.GetName(typeof(Season), e));
            PrintDic(dic);

            Console.ReadLine();
        }

        private static void PrintDic(Dictionary<Int32, String> dic)
        {
            foreach (KeyValuePair<Int32,String> item in dic)
            {
                Console.WriteLine("Key:{0}-----Value:{1}", item.Key, item.Value);
            }
        }
    }
}