HtmlHelper函數來填充下拉列表

Question

我想填充ASP.NET MVC中的下拉控件。我有一個名爲City的表，我從這個表中獲取記錄以通過實體數據填充。我已經使用ViewBag動態添加。但是它會引發編譯錯誤。

代碼

- 查看

<h4>City through db</h4> 
@Html.DropDownList(cities, "Select City"); 

控制器

public class HomeController : Controller 
    { 
     // GET: Home 
     public ActionResult Index() 
     { 
      ActionFilterdbEntities db = new ActionFilterdbEntities(); 
      var cities = db.Cities; 
      ViewBag.cities = new SelectList(cities, "Id", "CityName"); 
      return View(); 
     } 
    } 

型號

[Table("City")] 
    public class clCity 
    { 

     public int Id { get; set; } 
     public string CityName { get; set; } 

    } 
} 

Db的

CREATE TABLE [dbo].[City] (
    [Id]  INT   NOT NULL, 
    [CityName] NVARCHAR (50) NOT NULL, 
    PRIMARY KEY CLUSTERED ([Id] ASC) 
); 

Answer 1

你要構建這樣的下拉：

@Html.DropDownList("nameOfTheField", (SelectList)ViewBag.cities, "Select city"); 

如果你把這個下拉列表的形式，讓假設你有一個這樣的模型：

public class SearchModel 
{ 
    public int CityId { get; set; } 
    //etc 
} 

，那麼你會喜歡設置代碼如下：

@Html.DropDownList("CityId", (SelectList)ViewBag.cities, "Select city"); 

Answer 2

您認爲應該是這樣的：

<h4>City through db</h4> 
@Html.DropDownList("YourInputId", (SelectList)ViewBag.cities, "Select City") 

第一個參數是string將作爲重新返回標籤select的id和name屬性。

Answer 3

這個怎麼樣，

@{ 
    SelectList cities = ViewBag.cities; 
    } 
@Html.DropDownList("YourDropDownId", cities, "Select City") 

Answer 4

@Html.DropDownList("cities", ViewBag.cities as SelectList,"Select City") 

請使用上面的代碼。