綁定DropdownlistFor與Viewbag

Question

我想綁定DropDownListFor的助手與控制器中定義的viewbag。但我得到錯誤。

查看代碼： -

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

控制器代碼： -

收到

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();    
>   } 

錯誤： - System.Web.Mvc.HtmlHelper」不包含'DropDownListFor'的定義和最佳擴展方法重載'System.Web.M vc.Html.SelectExtensions.DropDownListFor（System.Web.Mvc.HtmlHelper，System.Linq.Expressions.Expression>，System.Collections.Generic.IEnumerable）'有一些無效參數

Answer 1

您需要更改

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

到

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

Answer 2

您也可以這樣做。它應該工作：

ViewBag.CurrencyID = x; 

，並考慮：

@Html.DropDownListFor(model => model.CurrencyID, null) 

希望這有助於！