利用枚举展示下拉列表

有时候我们想展示展示一个下拉列表，但又不想从数据库调用。这时我们可以通过枚举值来实现。

EnumHelper.cs

using System;
using System.Collections;
using System.Reflection;
using System.Web.UI.WebControls;
public class EnumHelper : System.Attribute
{
    private string _Author = string.Empty;
    private string _Description = string.Empty;
    private string _Url = string.Empty;


    /// <summary>
    /// 构造方法
    /// </summary>
    public EnumHelper()
    {
    }

    /// <summary>
    /// 构造方法
    /// </summary>
    /// <param name="description">描述</param>
    public EnumHelper(string description)
    {
        _Description = description;
    }


    /// <summary>
    /// 构造方法
    /// </summary>
    /// <param name="author">作者</param>
    /// <param name="description">描述</param>
    /// <param name="url">相关的Url</param>
    public EnumHelper(string author, string description, string url)
    {
        _Author = author;
        _Description = description;
        _Url = url;
    }



    /// <summary>
    /// 描述作者
    /// </summary>
    public string Author
    {
        get
        {
            return _Author;
        }
        set
        {
            _Author = value;
        }
    }

    /// <summary>
    /// 描述
    /// </summary>
    public string Description
    {
        get
        {
            return _Description;
        }
        set
        {
            _Description = value;
        }
    }

    /// <summary>
    /// 相关的Url
    /// </summary>
    public string Url
    {
        get
        {
            return _Url;
        }
        set
        {
            _Url = value;
        }
    }


    /// <summary>
    /// 得到某一个枚举项的RemarkAttribute
    /// </summary>
    /// <param name="en">枚举项</param>
    /// <returns>RemarkAttribute对象</returns>
    private EnumHelper GetRemarkAttributeFromEnumItem(System.Enum en)
    {
        Type type = en.GetType();
        FieldInfo f = type.GetField(en.ToString());

        EnumHelper ra = (EnumHelper)Attribute.GetCustomAttribute(f, typeof(EnumHelper));

        return ra;
    }

    /// <summary>
    /// 得到某一个枚举项的Remark描述
    /// </summary>
    /// <param name="en">枚举项</param>
    /// <returns>Remark的描述</returns>
    private string GetRemarkStringFromEnumItem(System.Enum en)
    {
        EnumHelper ra = GetRemarkAttributeFromEnumItem(en);

        string strDesp = string.Empty;

        if (ra != null)
            strDesp = ra.Description;
        else
            strDesp = en.ToString();

        return strDesp;
    }
    /// <summary>
    /// 根据当前枚举值获取Remark值
    /// </summary>
    /// <param name="enumType">类型</param>
    /// <param name="enumValue">值</param>
    /// <returns></returns>
    public string GetEnumName(Type enumType, string enumValue)
    {
        return GetRemarkStringFromEnumItem(
            (Enum)Enum.Parse(enumType, enumValue));
    }
    #region 使用枚举说明来填充下拉列表

    /// <summary>
    /// 使用枚举说明来填充下拉列表。
    /// </summary>
    /// <param name="ddl">下拉列表控件。</param>
    /// <param name="enumType"></param>
    public void SetEnumDropDownList(DropDownList ddl, Type enumType)
    {
        string[] nameList = Enum.GetNames(enumType);
        Array valueList = Enum.GetValues(enumType);
        for (int i = 0; i < nameList.Length; i++)
        {
            string typeName = GetRemarkStringFromEnumItem(
                (Enum)Enum.Parse(enumType, nameList[i]));
            string typeValue = ((int)((IList)valueList)[i]).ToString();
            ddl.Items.Add(new ListItem(typeName, typeValue));
        }

    }

    /// <summary>
    /// 使用枚举说明来填充下拉列表。
    /// </summary>
    /// <param name="enumType"></param>
    /// <param name="notShow">不显示的项的编号</param>
    public string SetEnumSelect(Type enumType, string notShow = "")
    {
        string selectList = string.Empty;
        string[] nameList = Enum.GetNames(enumType);
        Array valueList = Enum.GetValues(enumType);
        for (int i = 0; i < nameList.Length; i++)
        {
            string typeName = GetRemarkStringFromEnumItem(
                (Enum)Enum.Parse(enumType, nameList[i]));
            string typeValue = ((int)((IList)valueList)[i]).ToString();
            if (notShow != "")
            {
                string[] not = notShow.Split(',');

                if (!((IList)not).Contains(typeValue))
                {
                    selectList += " <option value='" + typeValue + "'>" + typeName + "</option>";
                }
            }
            else
            {
                selectList += " <option value='" + typeValue + "'>" + typeName + "</option>";
            }
        }
        return selectList;
    }

    public string GetEnumList(Type enumType)
    {
        string[] nameList = Enum.GetNames(enumType);
        string html = string.Empty;
        for (int i = 0; i < nameList.Length; i++)
        {
            if (html.Length > 0)
            {
                html += "," + GetRemarkStringFromEnumItem(
                      (Enum)Enum.Parse(enumType, nameList[i]));
               
            }
            else
            {
                html = GetRemarkStringFromEnumItem(
                (Enum)Enum.Parse(enumType, nameList[i]));
            }
        }
        return html;
    }

    #endregion


}

CityEnum.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test.Common.Enum
{
    public enum CityEnum
    {
        /// <summary>
        /// 石家庄
        /// </summary>
        [EnumHelper("石家庄")]
        ShiJiaZhuang=0,
        /// <summary>
        /// 保定
        /// </summary>
        [EnumHelper("保定")]
        BaoDing=1,
        /// <summary>
        /// 沧州
        /// </summary>
        [EnumHelper("沧州")]
        CangZhou=2
    }
}