DropDownList C＃Mvc4 Razor

Question

我不明白如何將這個selectListitem在控制器中傳遞，如何將它發送到視圖？ With return view("MyView", listItems)？但它說listItems在當前的情況下不存在！你有想法嗎？謝謝

@{ 
    List<SelectListItem> listItems= new List<SelectListItem>(); 
    listItems.Add(new SelectListItem 
     { 
      Text = "Exemplo1", 
      Value = "Exemplo1" 
     }); 
    listItems.Add(new SelectListItem 
     { 
      Text = "Exemplo2", 
      Value = "Exemplo2", 
      Selected = true 
     }); 
    listItems.Add(new SelectListItem 
     { 
      Text = "Exemplo3", 
      Value = "Exemplo3" 
     }); 
} 

@Html.DropDownListFor(model => model.tipo, listItems, "-- Select Status --") 

我確切地說，我已經有一個模型在我看來的形式。我想用下拉列表填寫表單的一個字段。這就是爲什麼我想使用HtmlHelper DropDownListFor。

Answer 1

您將要定義一個模型，並將該模型類傳遞到視圖中。溝ViewBag並使用強類型模型。

public class ViewModel 
{ 
    public int ddlSelectedValue {get; set;} 
    List<System.Web.Mvc.SelectListItem> DDLItems { get; set; } //Instantiate this through Constructor  
} 


ViewModel model = new ViewModel(); 

int val = 5; 
model.DDLItems.Add(new SelectListItem() { Text = "Text", Value = Val.ToString() }); 

return view (model) 

View 
@model NameSpace.ViewModel 


@Html.DropDownListFor(x => x.ddlSelectedValue, Model.DDLItems) 

Answer 2

何去何從視圖 @ {

List<User> listaUsers = (List<User>)ViewBag.ListUser; 

}

   foreach (User us in listaUsers) 
       { 

         <option value="@us.UserID">@us.Name</option> 

       } 

     </select> 


    /// Name function its like name of view for binding this part go to the controller 
    public ActionResult anytingName() 
    { 
     User us= new User(); 
     us.Name="paul"; 
     us.UserID=1; 
     List<User> users= new List<User>(); 
     users.Add(us); 
     ViewBag.ListUser = users; 
     return View(); 
    }