Dropdownlist with Selectlist Item

Question

I am trying to create a Select List, but in case it is returning it to my view:

Microsoft.AspNetCore.Mvc.Rendering.Selectlistitem

so is not returning the Cargos that are in my database

and here are the codes I use.

View:

@if (ViewBag.Office != null)
{
    @Html.DropDownList("Office", ViewBag.Office as SelectList, htmlAttributes: new { @class = "form-control" })
    <div class="input-group-append" data-toggle="modal" data-target="#cadastra-cargo">
        <a class="btn btn-default">Adicionar</a>
    </div>
    <span asp-validation-for="Office" class="text-danger"></span>
}
else
{
    <select class="form-control" asp-for="Office">
        <option value="">Adicione um cargo</option>
    </select>
     <div class="input-group-append" data-toggle="modal" data-target="#cadastra-cargo">
         <a class="btn btn-default">Adicionar</a>
     </div>
     <span asp-validation-for="Office" class="text-danger"></span>
}

Controller:

[HttpGet]
[AllowAnonymous]
public async Task<IActionResult> Add(string returnUrl = null)
{
   ViewData["ReturnUrl"] = returnUrl;

   var user = await _userManager.GetUserAsync(User);

   if (user == null)
   {
       throw new ApplicationException($"Não é possível carregar o usuário com o ID '{_userManager.GetUserId(User)}'.");
   }

   ViewBag.Office = _employeeManager.GetAllOfficeAsync(user.Id);

   return View();
}

Getallofficeasync service:

public SelectList GetAllOfficeAsync(Guid user)
{
    try
    {
        var lista = _context.FuncionariosCargo.Where(x => x.UsuarioId == user)
                                           .OrderBy(x => x.Cargo)
                                           .Select(c => new SelectListItem
                                           {
                                               Value = c.Id.ToString(),
                                               Text = c.Cargo
                                           });

            SelectList result = new SelectList(lista);



            return result;
        }
        catch (Exception)
        {
            throw;
        }

    }

Answer 1

Matheus, in your method: GetAllOfficeAsync

Add a validation to return your listing, if you return a blank list, pass Null instead of passing the List.

Try to do so:

    public SelectList GetAllOfficeAsync(Guid user)
{
    try
    {
        var lista = _context.FuncionariosCargo.Where(x => x.UsuarioId == user)
                                           .OrderBy(x => x.Cargo)
                                           .Select(c => new SelectListItem
                                           {
                                               Value = c.Id.ToString(),
                                               Text = c.Cargo
                                           });

            SelectList result = new SelectList(lista);

        if(result.count > 0)
        {
           return result;
        }
        else
        {
            return null;
        }
    }
    catch (Exception)
    {
        throw;
    }
}