ASP.NET MVC HtmlHelper =>Html.DropDownList

用法一：

Controller Action:

为什么为什么

        public ActionResult DropDownList()
        {
            NorthwindEntities ne = new NorthwindEntities();
            var p = ne.Categories;
            
            List<SelectListItem> items = new List<SelectListItem>();
            foreach(var n in p)
            {
                var item = new SelectListItem { Value  = n.CategoryID.ToString(), Text  = n.CategoryName };
                items.Add(item);
            }
            ViewData["l"] = items;
            return View();
            

View:

 

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2>CategoryDropDownList</h2>
<%=Html.DropDownList("l") %>
</asp:Content>