扩展htmlhelper.DropDownListFor 支持list数据源和option增加属性

 1 public static MvcHtmlString DropDownListForEx<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper,
 2             Expression<Func<TModel, object>> expression, Func<TModel, IEnumerable<TProperty>> options,
 3             Func<TProperty, string> optionText, Func<TProperty, string> optionValue, string optionLabel = null,
 4             Func<TProperty, IDictionary<string, object>> optionHtmlAttributes = null, IDictionary<string, object> htmlAttributes = null)
 5         {
 6 
 7             var tagNameAttr = ExpressionHelper.GetExpressionText(expression);
 8             TagBuilder tag = new TagBuilder("select");
 9             if (htmlAttributes != null)
10                 tag.MergeAttributes(htmlAttributes);
11             tag.MergeAttribute("name", tagNameAttr, true);
12             tag.GenerateId(tagNameAttr);
13 
14             StringBuilder optionsHtml = new StringBuilder();
15             var os = options(htmlHelper.ViewData.Model);
16             if (optionLabel != null)
17             {
18                 TagBuilder tag3 = new TagBuilder("option");
19                 tag3.SetInnerText(optionLabel);
20                 optionsHtml.AppendLine(tag3.ToString(TagRenderMode.Normal));
21             }
22 
23             foreach (var item in os)
24             {
25                 TagBuilder tag2 = new TagBuilder("option");
26                 tag2.SetInnerText(optionText(item));
27                 if (optionHtmlAttributes != null)
28                     tag2.MergeAttributes(optionHtmlAttributes(item));
29                 tag2.MergeAttribute("value", optionValue(item), true);
30                 var oHtml = tag2.ToString(TagRenderMode.Normal);
31                 optionsHtml.AppendLine(oHtml);
32             }
33 
34             tag.InnerHtml = optionsHtml.ToString();
35             return new MvcHtmlString(tag.ToString(TagRenderMode.Normal));
36         }

depInfos：List<>

 @Html.DropDownListForEx(p => p.DepCode, p => depInfos, p => p.Name, p => p.Id, "请选择", p => new Dictionary<string, object>() { { "data-tokens", p.NamePinYin+" "+p.NameFirstPinYin } }, new Dictionary<string, object> { { "class", "selectpicker" }, { "data-live-search", true } })