Load dropdown list from class asp.net core-CodePudding

I have a dropdown list on a view, this view adds users to the database. The dropdown list code is currently in the CreateUser() method in the users controller, and it works perfectly. I need to reuse this code throughout the application, so I created a new Class called stores and have created a method called LoadStoreList() and have moved the code from CreateUser() to this new method. The idea is obviously to call this LoadStoreList() method every time I need to poplate a drop down with the list of stores.

Controller I want to call the LoadStoreList() method from the CreateUser() method.

public IActionResult CreateUser()
{
    var getStoreList = new Stores();
    ViewBag.Stores = getStoreList.LoadStoreList();
    return View();
}

Stores Class

public class Stores
{
    private static ApplicationDbContext? _context;

    public Stores()
    {
    }

    public Stores(ApplicationDbContext context)
    {
        _context = context;
    }

    public IActionResult LoadStoreList()
    {
        var storeList = _context?.Stores.Select
                        (s => new SelectListItem { Value = s.StoreId.ToString(), Text = s.StoreName }).ToList();
        storeList?.Insert(0, new SelectListItem("-- Select --", ""));
        return (IActionResult)storeList;
    }
}

The issue I'm having is that the storeList object in the LoadStoreList method is always null , and I can't quite see where I'm going wrong.

Edit

private static ApplicationDbContext _context;

public Stores()
{
    _context = new ApplicationDbContext();
}

CodePudding user response：

Have a try:

1.make some change to your controller(replace LoopDroController with your controller):

 public class LoopDroController : Controller
        {
            private readonly ApplicationDbContext _context;
            public LoopDroController(ApplicationDbContext context)
            {
                _context = context;
            }
                     
            public IActionResult CreateUser()
            {
                var getStoreList = new Stores(_context);
                ViewBag.Stores = getStoreList.LoadStoreList();
                return View();
            }
        }

2.change your stores like below:

 public class Stores
    {
        private static ApplicationDbContext? _context;
        public Stores(ApplicationDbContext context)
        {
            _context = context;
        }

        public List<SelectListItem> LoadStoreList()
        {
            ar storeList = _context?.Stores.Select
                    (s => new SelectListItem { Value = s.StoreId.ToString(), Text = s.StoreName }).ToList();
            storeList?.Insert(0, new SelectListItem("-- Select --", ""));
            return storeList;
        }
    }

3.result: