Unable to execute a SQL Server stored procedure from Register.cshtml.cs in Blazor app

Question

I have a Players table in a SQL Server database and I'm trying to link it to the AspNetUsers table with a stored procedure during registration. However, when I attempt to call the procedure, this variable p is null. I'm new to this kind of coding, so please keep that in mind when responding.

Here's the section where the variable p is null from the Register.cshtml.cs file -

readonly PlayerInitClass p;

public async Task<IActionResult> OnPostAsync(string returnUrl = null)
{
        returnUrl = returnUrl ?? Url.Content("~/");
        ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();

        if (ModelState.IsValid)
        {
            var user = new ApplicationIdentityUser { UserName = Input.Email, Email = Input.Email };
            var result = await _userManager.CreateAsync(user, Input.Password);
            int pID = await p.InitPlayerAsync(user);
        }
}

Here is the class I created -

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;
using Scorekeeper.Data;

namespace Scorekeeper.Areas.Identity
{
    public class PlayerInitClass
    {
        private readonly ApplicationDbContext _db;

        public PlayerInitClass(ApplicationDbContext db)
        {
            _db = db;
        }

        public async Task<Int32> InitPlayerAsync(ApplicationIdentityUser user)
        {
            int AspNetUserId = user.Id;

            SqlParameter[] @params =
            {
              new SqlParameter("@returnVal", SqlDbType.Int) {Direction = ParameterDirection.Output},
              new SqlParameter("@AspNetUserId", SqlDbType.Int) {Direction = ParameterDirection.Input, Value = AspNetUserId},
          };

            await _db.Database.ExecuteSqlRawAsync("EXEC @returnVal=[dbo].[InitializeNewRegistrationPlayer] @AspNetUserId", @params);

            int result = Convert.ToInt32(@params[0].Value);

            await Task.FromResult(result);
            return result;
        }
    }
}

Here is the warning message I'm seeing about the Field p being null.

Answer 1

I ended up finding a way to not be null. As you can probably already tell, I am a newb and am blindly stumbling my way through this. That being said, I wouldn't feel comfortable saying this is the "right" answer to the question. Also, even though I got it to not be null it throws a different error now. If I can't figure it out I'll post a separate question.

Here is what I changed the PlayerInitClass to:

public class PlayerInitClass : Microsoft.EntityFrameworkCore.DbContext
{
public PlayerInitClass()
{
    this.context = context;
}

public PlayerInitClass context { get; set; }

And this is how I instantiated it (not sure if that's the right way to say it):

PlayerInitClass p = new PlayerInitClass();