asp.net-mvc - 将 DropdownlistFor 与 Viewbag 绑定(bind)

Question

我正在尝试将 DropDownListFor 助手与 Controller 中定义的 viewbag 绑定(bind)。但我收到错误。

查看代码:-

@Html.DropDownListFor(model => model.CurrencyID, ViewBag.CurrencyList as SelectListItem)) 

Controller 代码:-

 public ActionResult Create()
>  {
>    var content = from p in db.Currency
>                  where p.IsActive == true
>                  orderby p.CurrencyName
>                  select new { p.CurrencyID, p.CurrencyCode };
> 
>    var x = content.ToList().Select(c => new SelectListItem         
>                            {
>                               Text = c.CurrencyCode,
>                               Value = c.CurrencyID.ToString(),
>                               Selected = (c.CurrencyID == 68)
>                            }).ToList();
>             ViewBag.CurrencyList = x;
> 
>             return View();            
>         }

收到错误:-
System.Web.Mvc.HtmlHelper'不包含'DropDownListFor'的定义和最佳扩展方法重载'System.Web.Mvc.Html.SelectExtensions.DropDownListFor(System.Web.Mvc.HtmlHelper, System.Linq.Expressions. Expression>, System.Collections.Generic.IEnumerable)' 有一些无效参数

Answer 1

你需要改变

@Html.DropDownListFor(model => model.CurrencyID, ViewBag.CurrencyList as SelectListItem))

到

@Html.DropDownListFor(model => model.CurrencyID, ViewBag.CurrencyList as IEnumerable<SelectListItem>)