自定义属性_使枚举得到描述信息

//方法:  

 public static string GetEnumDescription<TEnum>(object value)
        {

            Type enumType = typeof(TEnum);

            if (!enumType.IsEnum)
            {
                throw new ArgumentException("enumItem requires a Enum ");
            }

            var name = Enum.GetName(enumType, Convert.ToInt32(value));
            if (name == null)
                return string.Empty;

            object[] objs = enumType.GetField(name).GetCustomAttributes(typeof(DescriptionAttribute), false);

            if (objs == null || objs.Length == 0)
            {
                return string.Empty;
            }
            else
            {
                DescriptionAttribute attr = objs[0] as DescriptionAttribute;

                return attr.Description;
            }
        }

// 调用:

string desc=GetEnumDescription<Filter>(Filter.Public); //得到Filter(enum)中,为Public 所定义的描述信息.

// Filter枚举的描述:

 public enum Filter
    {
        /// <summary>
        /// 全部
        /// </summary>
        [Description("全部")]
        All = 1,

        /// <summary>
        /// 已分配
        /// </summary>
        [Description("已分配")]
        Assigned = 2,

        /// <summary>
        /// 待分配
        /// </summary>
        [Description("待分配")]
        Assigning = 3,

        /// <summary>
        /// 返回调整
        /// </summary>
        [Description("返回调整")]
        Adjusting = 4,

        /// <summary>
        /// 已拒绝
        /// </summary>
        [Description("已拒绝")]
        Reject = 5,

        /// <summary>
        /// 公共
        /// </summary>
        [Description("公共")]
        Public = 6,
        /// <summary>
        /// Sales把发回调整的客户编辑后不先提交只保存信息
        /// </summary>
        [Description("草稿")]
        Draft = 7,
        /// <summary>
        /// 排队
        /// </summary>
        [Description("排队")]
        InQueue = 8,
        /// <summary>
        /// 发放给大区经理审批
        /// </summary>
        [Description("审批转移")]
        ToManagerCheck = 9,

        /// <summary>
        /// 不返回任何值的条件
        /// </summary>
        None = -1,

    }

//4, DescriptionAttribute 的定义:

public class DescriptionAttribute : Attribute
    {
        public DescriptionAttribute(string desc);

        public string Description { get; set; }
    }

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 public partial class 枚举_Enum_自定义属性 : System.Web.UI.Page
    {
        protected void Page_Load(object sender , EventArgs e)
        {
            string desc = GetEnumDescription<MyColorEnum>(MyColorEnum.red);
            //desc = GetEnumDescription<MyColorEnum>(1);
            Response.Write(desc);

        }

        public enum MyColorEnum
        {
            [DescriptionAttribute("红色")]
            red ,
            [DescriptionAttribute("蓝色")]
            blue ,
            [DescriptionAttribute("绿色")]
            green ,
            [DescriptionAttribute("白色")]
            white
        }

        //其实这个属性已经有了:
        //public class DescripteAttribute : Attribute
        //{
        //    public DescripteAttribute(string desc)
        //    {
        //        this._description = desc;
        //    }
        //    private string _description;

        //    public string Description
        //    {
        //        get
        //        {
        //            return this._description;
        //        }
        //        set
        //        {
        //            this._description = value;
        //        }
        //    }
        //}

        /// <summary>
        /// 获取枚举项的描述
        /// </summary>
        /// <param name="enumItem">具体枚举类型</param>
        /// <returns></returns>
        public static string GetEnumDescription<TEnum>(object value)
        {
            Type enumType = typeof(TEnum);

            if(!enumType.IsEnum)
            {
                throw new ArgumentException("不是枚举类型");
            }

            string enumItem = Enum.GetName(enumType , Convert.ToInt32(value));
            if(enumItem == null)
            {
                return string.Empty;
            }

            object[] objs = enumType.GetField(enumItem).GetCustomAttributes(typeof(DescriptionAttribute) , false);

            if(objs == null || objs.Length == 0)
            {
                return string.Empty;
            }
            else
            {
                DescriptionAttribute attr = objs[0] as DescriptionAttribute;

                return attr.Description;
            }
        }
    }