MVC Core SelectList Dropdown in Controller Error “Microsoft.AspNetCore.Mvc.Rendering.SelectListItem”

Question

I want to create a SelectList Dropdown in MVC.

I prefer select list to be in repository, not in controller. How do I call a repository, without even referring to the nam

Answer 1

Your current GetAllLookupKey would not compile! Use this version.

public IEnumerable<SelectListItem> GetAllLookupKey()
{
    return _context.ProductType.Select( pt=>new SelectListItem
    {
        Value = pt.ProductTypeName,
        Text = pt.ProductDescription
    }).ToList();
}

Also, there is no need to create a second SelectList. Your GetAllLookupKey method returns a collection of SelectListItem and you can set that to your ViewData.

 ViewData["ProductTypeId"] = _producttyperepository.GetAllLookupKey();

The SelectListItem class is defined in the namespace Microsoft.AspNetCore.Mvc.Rendering; So make sure you have a using statement which includes that namespace in your class.

using Microsoft.AspNetCore.Mvc.Rendering;

If this is in a different project than the one which has the Controllers. make sure your project has a reference to the assembly which has this namespace & class.

While that might fix our problem, SelectListItem is a class to represent more of a UI layer concern. IMHO, You should not have your repository return that. Have your repository return more generic data (Ex : List of ProductType) and have your UI layer code (controller action/UI service layer etc) generate the list of SelectListItem objects from this ProductType list.