c# - 如何使用模型在 mvc 4 的局部 View 中绑定(bind)下拉列表？

Question

您好，我在 index.cshtml 页面中使用局部 View 。部分 View 包含一个从数据库动态绑定(bind)的下拉列表。

我不想使用 viewbag 或 viewdata 来绑定(bind)这个下拉列表。

在 Controller 中

    // GET: Reporting/Home
    public ActionResult Index()
    {
        var view = View();

        return view;
    }

    public ActionResult _ReportingMenu()
    {
        var DashboardList = GetAllDashboards();

        return View(DashboardList);
    }


    public IEnumerable<DashboardDefinition> GetAllDashboards()
    {
        return _reortDefinitionService.GetAllDashboards();
    } 

在 index.cshtml 中

@model IEnumerable<Portal.Domain.ReportingModule.ReportDefinition.DashboardDefinition>

@{
    ViewBag.Title = "Reporting";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Reporting View</h2>
@Html.ActionLink("Add new Chart", "Create", "Chart", new { area = "Reporting" }, null)

@Html.Partial("_ReportingMenu")

在局部 View 中

    @model  Portal.Domain.ReportingModule.ReportDefinition.DashboardDefinition

    <div class="nav navbar navbar-default navbar-no-margin submenu">

        @Html.DropDownList("Mobiledropdown1",IEnumerable<Model.DashboardName>)   

        <a id="SubMenuIntegratorNew" class="btn btn-default submenu-item" href="#">
            <i class="fa fa-file-o fa-lg"></i>
            <span class="submenu-item-text">New</span>
        </a>
        <a id="SubMenuIntegratorSave" class="btn btn-default submenu-item" href="#">
            <i class="fa fa-floppy-o fa-lg"></i>
            <span class="submenu-item-text">Save</span>
        </a>
        <a id="SubMenuIntegratorSaveAs" class="btn btn-default submenu-item" href="#">
            <i class="fa fa-files-o  fa-lg"></i>
            <span class="submenu-item-text">Save As</span>
        </a>
        <a id="SubMenuIntegratorAddChart" class="btn btn-default submenu-item" href="#">
            <i class="fa fa-picture-o fa-lg"></i>
            <span class="submenu-item-text">Add Chart</span>
        </a>
    </div>

但我收到空模型错误。

我不知道如何在局部 View 中实现

Answer 1

您应该使用 View 模型，这样您就可以在其中同时包含列表和选定的属性，例如:

public class DashboardViewModel
{
    public IEnumerable<SelectListItem> Data { get; set; }
    //Might not be an int, but just an example
    public int SelectedId { get; set; }
}

然后将其填充到您的 Controller 中:

public ActionResult _ReportingMenu()
{
    var DashboardList = GetAllDashboards();

    var dropdownData = DashboardList
        .Select(d => new SelectListItem
        {
            Text = d.Name, //Need to apply the correct text field here
            Value = d.Id.ToString() //Need to apply the correct value field here
        })
        .ToList();

    var model = new DashboardViewModel
    {
       Data = dropdownData 
    };

    return View(model);
}

然后在你的两个 View 中，设置模型:

 @model DashboardViewModel

然后在你的部分你可以做:

 @Html.DropDownListFor(m => m.SelectedId, Model.Data)