Question

我有一个HomeController，它有一个Navigation ActionResult来执行查询以获得顶级元素：

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    return View(navigationModel);
}

然后我有一个导航视图，输出结果如下：

@model IEnumerable<WebApplication1.Models.Navigation>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
    }
</ul>

我想添加第二个导航层，以便考虑如下：

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    var contentModel = (from n in db.Contents where (n.NavigationId = navigationModel.Id) orderby n.Position select n);
    return View(navigationModel, contentModel);
}

我收到错误Cannot convert method group 'Id' to non-delegate type 'int?'. Did you intend to invoke the method?

我还想将第二个查询传递给View，例如：

@model IEnumerable<WebApplication1.Models.Navigation>
@model IEnumerable<WebApplication1.Models.Contents>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
        <ul>
        @foreach (var item in Model)
            {
                @Html.MenuLink(item.Title, "Article", "Home")
            }
        </ul>
    }
</ul>

我意识到我对模型的使用可能完全不准确，只是想强调哪些数据在哪里。

非常感谢任何帮助： - ）

以下是帮助解决方案的导航和内容类：

Navigation.cs

public partial class Navigation
{
    public int Id { get; set; }
    public string Title { get; set; }
    public Nullable<int> Position { get; set; }
    public bool Main { get; set; }
    public string Action { get; set; }
    public string Controller { get; set; }
}

Content.cs

public partial class Content
{
    public int Id { get; set; }
    public Nullable<int> NavigationId { get; set; }
    public string Title { get; set; }
    public string Content1 { get; set; }
    public Nullable<int> Position { get; set; }
    public string Image { get; set; }
    public string Sub { get; set; }
    public Nullable<bool> Active { get; set; }
    public string Url { get; set; }
    public string Summary { get; set; }
}

尽管有用的建议我仍然留下错误Operator '==' cannot be applied to operands of type 'int?' and 'method group'所以尝试了另一种方法，即使用连接查询，所以我修改了MVC结构如下：

NavigationViewModel

public class NavigationViewModel
{
    public int NavigationId { get; set; }
    public string NavigationTitle { get; set; }
    public string NavigationAction { get; set; }
    public string NavigationController { get; set; }

    public int ContentId { get; set; }
    public string ContentTitle { get; set; }
}

的HomeController

public ActionResult Navigation()
{
    var navigationModel = from c in db.Contents
                            join n in db.Navigations on c.NavigationId equals n.Id
                            where (n.Main == true && c.Active == true)
                            orderby n.Position
                            select new NavigationViewModel()
                            {
                                NavigationId= n.Id,
                                NavigationTitle = n.Title,
                                NavigationAction = n.Action,
                                NavigationController = n.Controller,
                                ContentId = c.Id,
                                ContentTitle = c.Title
                            };

    return View(navigationModel);
}

导航

@model IEnumerable<WebApplication1.Models.NavigationViewModel>

@foreach (var item in Model)
{
    @item.NavigationId @item.NavigationTitle @item.NavigationAction @item.NavigationController @item.ContentId @item.ContentTitle
}

所以这得到了数据，但是我遇到了类似的问题，我现在如何逐步完成数据，所以我有这样的事情：

<ul class="nav sf-menu clearfix">
// Loop through items
// Are there multiple intances of the NavigationId?
    // No
    <li>navigation link here</li>
    // Yes
    <li class="sub-menu">navigation link here
        <ul>
            // Loop through all content links
            <li>content link here</li>
            // End loop
        </ul>
    </li>
// End Loop
</ul>

Answer 1

您可以使用视图模型：

public class NavigationViewModel
{
    public IEnumerable<Navigation> Navigations { get; set; }
    public IEnumerable<Content> Contents { get; set; }
}

您的视图将采用此视图模型：

@model YourNamespace.ViewModels.NavigationViewModel

您的控制器将初始化此视图模型并将其传递给视图：

public ActionResult Navigation() {
    var navigations = your query...
    var contents = your other query...

    return View(new NavigationViewModel {
        Navigations = navigations,
        Contents = contents
    });
}

您的观点可以访问Model.Navigations和Model.Contents。

Answer 2

尝试使用==而不是=来编译错误（除非你真的打算调用我怀疑的代理）。

public ActionResult Navigation()
{
    var navigationModel = (from m in db.Navigations where (m.Main == true) orderby m.Position select m);
    var contentModel = (from n in db.Contents where (n.NavigationId.HasValue &&(n.NavigationId.value == navigationModel.Id)) orderby n.Position select n);
    return View(new Tuple<Navigation, Contents> (navigationModel, contentModel));
}

如果您有施法并发症，则可能必须使用toString（）等转换。

对于第二个问题，如果您不想创建新课程，请使用元组（http://www.dotnetperls.com/tuple）。

@model Tuple<WebApplication1.Models.Navigation, WebApplication1.Models.Contents>

<ul class="nav sf-menu clearfix">
    @foreach (var item in Model.Item1)
    {
        @Html.MenuLink(item.Title, item.Action, item.Controller)
        <ul>
        @foreach (var item in Model.Item2)
            {
                @Html.MenuLink(item.Title, "Article", "Home")
            }
        </ul>
    }
</ul>

MVC 5传递2个查询以查看

2 个答案: