利用枚举展示下拉列表

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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}

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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    }}

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