C# 給枚舉定義DescriptionAttribute，把枚舉轉換為鍵值對

在C#中，枚舉用來定狀態值很方便，例如我定義一個叫做Season的枚舉

public enum Season
    {
        Spring = 1,
        Summer = 2,
        Autumn = 3,
        Winter = 4
    }

枚舉名是不能出現空格,()-/等字符

我們想把Spring顯示為春天，我們要自己定義說明信息，我們可以使用DescriptionAttribute，如下

public enum Season
    {
        [Description("春 天")]
        Spring = 1,
        [Description("夏 天")]
        Summer = 2,
        //[Description("秋 天")]
        Autumn = 3,
        [Description("冬 天")]
        Winter = 4
    }

下面我們來寫個擴展方法，來得到枚舉的說明信息，如下

        /// <summary>
        /// 擴展方法，獲得枚舉的Description
        /// </summary>
        /// <param name="value">枚舉值</param>
        /// <param name="nameInstead">當枚舉值沒有定義DescriptionAttribute，是否使用枚舉名代替，默認是使用</param>
        /// <returns>枚舉的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;
        }

 把枚舉轉換為鍵值對集合

/// <summary>
        /// 把枚舉轉換為鍵值對集合
        /// </summary>
        /// <param name="enumType">枚舉類型</param>
        /// <param name="getText">獲得值得文本</param>
        /// <returns>以枚舉值為key，枚舉文本為value的鍵值對集合</returns>
        public static Dictionary<Int32, String> EnumToDictionary(Type enumType, Func<Enum, String> getText)
        {
            if (!enumType.IsEnum)
            {
                throw new ArgumentException("傳入的參數必須是枚舉類型！", "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;
        }

我們把上面兩個方法放入名為EnumUtil的靜態類中。

下面是使用方法

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;
            //打印枚舉名
            Console.WriteLine(spring.ToString());
            //打印枚舉說明
            Console.WriteLine(spring.GetDescription());

            //枚舉轉換為鍵值對集合
            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);
            }
        }
    }

輸出結果如下

Spring
春 天
Key:1-----Value:春 天
Key:2-----Value:夏 天
Key:3-----Value:Autumn
Key:4-----Value:冬 天
Key:1-----Value:春 天
Key:2-----Value:夏 天
Key:3-----Value:
Key:4-----Value:冬 天
Key:1-----Value:Spring
Key:2-----Value:Summer
Key:3-----Value:Autumn
Key:4-----Value:Winter
Key:1-----Value:Spring
Key:2-----Value:Summer
Key:3-----Value:Autumn
Key:4-----Value:Winter

 

源代碼：http://files.cnblogs.com/jm6041/EnumUtil.rar