MVC 枚举绑定 DropDownList

         /// <summary>
         /// 枚举转化下拉列表数据集
         /// </summary>
         /// <param name="type">类型</param>
         /// <param name="selected">选中项</param>
         /// <returns>结果</returns>
         public static IEnumerable<SelectListItem> EnumToListItem(Type type, string selected)
         {
             IList<SelectListItem> list = new List<SelectListItem> { new SelectListItem { Text = "全部", Value = string.Empty } };
             Array array = Enum.GetValues(type);
             foreach (int item in array)
             {
                 string text = Enum.GetName(type, item);
                 var selectListItem = new SelectListItem
                 {
                     Text = text,
                     Value = item.ToString(CultureInfo.InvariantCulture),
                     Selected = !string.IsNullOrEmpty(selected) && selected == text
                 };
                 list.Add(selectListItem);
             }

             return list;
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="name">name</param>
         /// <param name="selectList">下拉列表集合</param>
         /// <param name="obj">属性</param>
         /// <returns>MvcHtmlString</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList, object obj)
         {
             string fullName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(name);
             if (string.IsNullOrEmpty(fullName))
             {
                 throw new ArgumentException("name");
             }

             StringBuilder listItemBuilder = new StringBuilder();
             foreach (SelectListItem item in selectList)
             {
                 TagBuilder builder = new TagBuilder("option")
                 {
                     InnerHtml = HttpUtility.HtmlEncode(item.Text)
                 };

                 if (item.Value != null)
                 {
                     builder.Attributes["value"] = item.Value;
                 }

                 if (item.Selected)
                 {
                     builder.Attributes["selected"] = "selected";
                 }

                 listItemBuilder.AppendLine(builder.ToString(TagRenderMode.Normal));
             }

             TagBuilder tagBuilder = new TagBuilder("select")
             {
                 InnerHtml = listItemBuilder.ToString()
             };

             if (obj != null)
             {
                 IDictionary<string, object> htmlAttributes = new RouteValueDictionary(obj);
                 tagBuilder.MergeAttributes(htmlAttributes);
             }
             tagBuilder.MergeAttribute("name", fullName, true);
             tagBuilder.GenerateId(fullName);

             return new MvcHtmlString(tagBuilder.ToString(TagRenderMode.Normal));
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="name">name</param>
         /// <param name="selectList">下拉列表集合</param>
         /// <returns>MvcHtmlString</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList)
         {
             return DropDownList(htmlHelper, name, selectList, null);
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="type">枚举类型</param>
         /// <param name="name">name属性</param>
         /// <param name="selected">选择项目</param>
         /// <param name="obj">其他属性</param>
         /// <returns>DropDownList</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, Type type, string name, string selected, object obj)
         {
             IEnumerable<SelectListItem> selectListItem = EnumToListItem(type, selected);
             return DropDownList(htmlHelper, name, selectListItem, obj);
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="type">枚举类型</param>
         /// <param name="name">name属性</param>
         /// <param name="selected">选择项目</param>
         /// <returns>DropDownList</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, Type type, string name, string selected)
         {
             return DropDownList(htmlHelper, type, name, selected, null);
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="type">枚举类型</param>
         /// <param name="name">name属性</param>
         /// <param name="obj">其他属性</param>
         /// <returns>DropDownList</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, Type type, string name, object obj)
         {
             return DropDownList(htmlHelper, type, name, null, obj);
         }

         /// <summary>
         /// 自定义DropDownList
         /// </summary>
         /// <param name="htmlHelper">htmlHelper</param>
         /// <param name="type">枚举类型</param>
         /// <param name="name">name属性</param>
         /// <returns>DropDownList</returns>
         public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, Type type, string name)
         {
             return DropDownList(htmlHelper, type, name, null, null);
         }