Asp.Net MVC DropDownList 数据绑定 [英] Asp.Net MVC DropDownList Data Binding

问题描述

                    <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这个 DropDownList.我的意思是如何在控制器类的操作方法中获取 dropDownList 的值.谢谢.

I want to bind this DropDownList in controller. I mean how can I get the value of the dropDownList in the action method in controller class. Thanks.

推荐答案

我看到您正在使用带有 runat="server" 和 asp:XXX 网络控件的表单.这些是永远不应在 ASP.NET MVC 中使用的概念.这些服务器控件不再依赖于 ViewState 和 PostBack.

I see that you are using forms with runat="server" and asp:XXX web controls. Those are notions should never be used in ASP.NET MVC. There is no more ViewState and PostBacks that those server controls rely on.

因此，在 ASP.NET MVC 中，您首先要定义一个表示数据的视图模型:

So in ASP.NET MVC you would start by defining a view model representing the data:

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

然后您将定义一个具有两个动作的控制器(一个用于呈现视图，另一个用于处理表单提交):

then you would define a controller with two actions (one that renders the view and another that handles the form submission):

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
        ...
    }
}

最后你将编写相应的强类型Index视图:

and finally you would write the corresponding strongly typed Index view:

<%@ 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>

据说您也可以在视图中对此选择进行硬编码(尽管我不推荐这样做):

This being said you could also hardcode this select inside your view (although this is something I wouldn't recommend):

<% 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" />
<% } %>

并具有以下控制器:

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
        ...
    }
}

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