在 _Header 部分中，如何从 db 查询到呈现菜单？

Question

Layout:

<partial name="_HeaderPartial" />
<div class="container">
    <main role="main" class="pb-3">
        @RenderBody()
    </main>
</div>
<partial name="_FooterPartial" />

_Header:

<header>
<nav class="navbar navbar-expand-sm navbar-toggleable-sm navbar-light bg-white border-bottom box-shadow mb-3">
    <div class="container">
        <a class="navbar-brand" asp-controller="Home" asp-action="Index">Admin</a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target=".navbar-collapse" aria-controls="navbarSupportedContent"
                aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>
        <div class="navbar-collapse collapse d-sm-inline-flex flex-sm-row-reverse">
            <ul class="navbar-nav flex-grow-1">
                <li class="nav-item">
                    <a class="nav-link text-dark" asp-controller="Home" asp-action="Index">Home</a>
                </li>
            </ul>
        </div>
    </div>
</nav>

Now I need to replace nav-item , each page route and name comes from databse. Since there is not a particular corresponded controller for header partial.

So do I have to add ViewBag in each controller? like this:

    public IActionResult Index() // page1
    {
        ViewBag.menus = _svc.getMenu(); 
        return View();
    }

    public IActionResult Thanks() // page2
    {
        ViewBag.menus = _svc.getMenu(); 
        return View();
    }

_Header

                @foreach (var menmu in ViewBag.menus)
                {
                    <li class="nav-item">
                        <a class="nav-link text-dark" asp-controller="@menmu.controller" asp-action="@menmu.action">@menmu.title</a>
                    </li>
                }

I mean I konw its not right to do so, but I don't know what is the best way to figure it out.

Answer 1

I have done this as follows (in an MVC5 app, it looks like you are using Razor Pages so for you it may be different, but I think it can still help you)

1. Create a menu partial view, with it's own Menu model class. Place the markup for your menu there
2. Add a Menu() method to your HomeController (or some other controller, doesn't really matter), that returns a PartialViewResult. I've marked it as [ChildActionOnly] to make sure it can only be used as partial view. I also added [OutPutCache(Duration = 60)] This method will get the data, create the model and return a call to PartialView("_Menu, menuModel) (or whatever you named the partial view and model)
3. In your header, add @Html.Action("Menu", "Home") to render the menu