Asp.Net MVC DropDownList数据绑定

Question

                    <form id="Form1" runat="server">
                        <asp:DropDownList ID="dvmDrmList" runat="server">
                            <asp:ListItem>Theory</asp:ListItem>
                            <asp:ListItem>Appliance</asp:ListItem>
                            <asp:ListItem>Lab</asp:ListItem>
                        </asp:DropDownList>
                    </form>

我想在控制器中绑定此DropDownList.我的意思是如何在控制器类的action方法中获取dropDownList的值.谢谢.

Answer 1

我看到你正在使用表单runat="server"和asp:XXXweb控件.这些概念永远不应该在ASP.NET MVC中使用.这些服务器控件不再依赖于ViewState和PostBack.

因此,在ASP.NET MVC中,您将首先定义表示数据的视图模型:

public class ItemsViewModel
{
    public string SelectedItemId { get; set; }
    public IEnumerable<SelectListItem> Items { get; set; }
}

那么你将定义一个带有两个动作的控制器(一个呈现视图,另一个呈现表单提交):

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new ItemsViewModel
        {
            Items = new[]
            {
                new SelectListItem { Value = "Theory", Text = "Theory" },
                new SelectListItem { Value = "Appliance", Text = "Appliance" },
                new SelectListItem { Value = "Lab", Text = "Lab" }
            }
        };
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(ItemsViewModel model)
    {
        // this action will be invoked when the form is submitted and 
        // model.SelectedItemId will contain the selected value
        ...
    }
}

最后你会写出相应的强类型Index视图:

<%@ Page 
    Language="C#" 
    MasterPageFile="~/Views/Shared/Site.Master" 
    Inherits="System.Web.Mvc.ViewPage<AppName.Models.ItemsViewModel>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Home Page
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <% using (Html.BeginForm()) { %>
        <%= Html.DropDownListFor(x => x.SelectedItemId, new SelectList(Model.Items, "Value", "Text")) %>
        <input type="submit" value="OK" />
    <% } %>
</asp:Content>

这就是说你也可以在你的视图中硬编码这个选择(虽然这是我不推荐的):

<% using (Html.BeginForm()) { %>
    <select name="selectedItem">
        <option value="Theory">Theory</option>
        <option value="Appliance">Appliance</option>
        <option value="Lab">Lab</option>
    </select>
    <input type="submit" value="OK" />
<% } %>

并拥有以下控制器:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View();
    }

    [HttpPost]
    public ActionResult Index(string selectedItem)
    {
        // this action will be invoked when the form is submitted and 
        // selectedItem will contain the selected value
        ...
    }
}