ASP.Net Core 5 MVC Populate a drop down list with Database records-CodePudding

Title states what I'm trying to do.

Controller method:

public IActionResult Create()
        {
            IEnumerable<string> hList = from char s in _context.NR_Users select s.ToString();

            List < NR_User > hUsers = new List<NR_User>();
            hUsers = (from c in _context.NR_Users select c).ToList();
            hUsers.Insert(0, new NR_User { ID = 0, Name = "Select" });
            ViewBag.historyUsers = hUsers;

            List<SelectListItem> options = new()
            {
                new SelectListItem { Value = "True", Text = "Yes" },
                new SelectListItem { Value = "False", Text = "No" }
            };
            ViewBag.options = options;
            return View();
        }

View:

<div class="form-group col-md-4">
                    <label class="control-label">History PM</label>
                    <select asp-for="History_PM" name="History_PM" class="form-control" asp-items="@ViewBag.historyUsers"></select>
                    <span asp-validation-for="History_PM" class="text-danger"></span>
                </div>

But when I run the app and navigate to the Create page I get this error:

RuntimeBinderException: Cannot implicitly convert type 'System.Collections.Generic.List<EnvApp.Models.DB.NR_User>' to 'System.Collections.Generic.IEnumerable<Microsoft.AspNetCore.Mvc.Rendering.SelectListItem>'. An explicit conversion exists (are you missing a cast?)

I understand that it can't implicitly convert the list to an IEnumerable, but how exactly do I do that?

CodePudding user response：

You can convert the list using SelectList class.

Try replacing

<select asp-for="History_PM" name="History_PM" class="form-control" asp-items="@ViewBag.historyUsers"></select>

with

<select asp-for="History_PM" name="History_PM" class="form-control" asp-items="@(new SelectList(ViewBag.historyUsers, "ID", "Name"))"></select>