Asp.Net MVC DropDownList的数据绑定 [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>

我想这个DropDownList的控制器中进行绑定。我的意思是我怎么能得到DROPDOWNLIST的价值在控制器类的动作方法。谢谢你。

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

我看到你使用表单的 =服务器和 ASP：XXX Web控件。这些都是概念不应该在ASP.NET MVC中使用。有没有更多的ViewState和回传，那些服务器控件的依赖。

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，你会通过定义视图模型重新presenting数据开始：

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; }
}

那么就需要定义有两个动作控制器（一个呈现的观点，另一种是处理提交表单）：

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
        ...
    }
}

最后你会写相应的强类型首页查看：

<%@ 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，你还可以硬code此选择您的视图中（虽然这是我不会推荐）：

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" />
<% } %>

和具有以下控制器：

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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