How to send data from a controller to the dropdown list in _Layout.cshtml file?

Question

I am trying to send retrieved data from database in a controller to the '_Layout.cshtml' file. But not sure how can I pass the data from the controller to the _Layout.cshtml. Does anyone know how to do it?

Why not you make a call from the page where you need those data? — Sabir Hossain, Aug 04 '19 at 03:27

score 1 · Accepted Answer · answered Aug 05 '19 at 03:18

For passing data from Controller to View, there are three options below:

Strongly typed data: viewmodel
Weakly typed data
- ViewData (ViewDataAttribute)
- ViewBag

If you want to return different value from Controller to _Layout.cshtml, you could try ViewData.

Example:

Model

public class UserVM
{
    public int UserId { get; set; }
    public string Value { get; set; }
}

Layout.cshtml

@using Microsoft.AspNetCore.Hosting
@{ 
    var users = ViewData["Users"] as List<UserVM>;
}
<!DOCTYPE html>
<html>
<body>

    <div class="container">
        <partial name="_CookieConsentPartial" />
        <main role="main" class="pb-3">
            @foreach (var user in users)
            {
                <div>@user.Value</div>
            }
            @RenderBody()
        </main>
    </div>    

    @RenderSection("Scripts", required: false)
</body>
</html>

Controller Action

public async Task<IActionResult> Index()
{
    ViewData["Users"] = new List<UserVM> {
        new UserVM{ UserId = 1, Value = "Tom"},
        new UserVM{ UserId = 2, Value = "Jack"},
        new UserVM{ UserId = 3, Value = "Vicky"}
    };            
    return View();
}

score 0 · Answer 2 · answered Aug 04 '19 at 03:19

0

Try using ViewData or ViewBag to pass data to dropdown. The below link might help Link

answered Aug 04 '19 at 03:19

Ajoe

1,397
4
19
48

But '_Layout.cshtml' view doesn't have any controller – Aug 04 '19 at 04:07
@JatinKumar _Layout.cshtml does not need to have a `Controller` if you are using Templating, just pass the `ViewBag`, in all the `Controller` of all the pages that use the _Layout. – Bosco Aug 05 '19 at 05:22

score 0 · Answer 3 · answered Aug 04 '19 at 12:49

You can create some service and inject in your layout.cshtml

Something like this

@inject MyService myService

@if(await myService.GetListOfData()) {
  // display data here
}

So in your serivce you can write like the nomarl service

public class MyService
{
    private readonly IRepository<ObjectDTO> _repo;
    public MyService(IRepository<ObjectDTO> repo)
    {
        _repo = repo;
    }

    public async Task<bool> GetListOfData()
    {
        var data = await _repo.Where(); // something
        return data;
    }
}

How to send data from a controller to the dropdown list in _Layout.cshtml file?

3 Answers3