I have error : InvalidOperationException: Unable to resolve service for type while attempting to activate controller

Question

I have error when I make web app with EF 6.0.

InvalidOperationException: Unable to resolve service for type 'WebbyMyself.Models.StudentManageEntities' while attempting to activate 'WebbyMyself.Controllers.BranchesController'.

It has Models/StudentManageEntities.cs:

using Microsoft.EntityFrameworkCore;

namespace WebbyMyself.Models
{
    public class StudentManageEntities : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBulder)
        {
            optionsBulder.UseSqlServer(
                "*connetion string of my database*"
            );
        }
        public virtual DbSet<Branch> Branch { get; set; }
    }
}

And Controllers/BranchController.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using WebbyMyself.Models;

namespace WebbyMyself.Controllers
{
    public class BranchController : Controller
    {
        private readonly StudentManageEntities _context;

        public BranchController(StudentManageEntities context)
        {
            _context = context;
        }

        // GET: Branch
        public async Task<IActionResult> Index()
        {
              return View(await _context.Branch.ToListAsync());
        }
    }
}

And Views/Branch/Index.cshtml:

@model IEnumerable<WebbyMyself.Models.Branch>

@{
    ViewData["Title"] = "Index";
}

<h1>Index</h1>

<p>
    <a asp-action="Create">Create New</a>
</p>                            
<table class="table">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.BranchName)
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
@foreach (var item in Model) {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.BranchName)
            </td>
            <td>
                <a asp-action="Edit" asp-route-id="@item.ID">Edit</a> |
                <a asp-action="Details" asp-route-id="@item.ID">Details</a> |
                <a asp-action="Delete" asp-route-id="@item.ID">Delete</a>
            </td>
        </tr>
}
    </tbody>
</table>

I use Code Generation in Visual Studio 2022.

I don't know how to fix, so pls help me.

I don't know how to describe so if you want more information pls tell me. Thank you so much.

Answer 1

You need to register your DbContext class with name "StudentManageEntities" like this on Program.cs file:

services.AddDbContext<StudentManageEntities>();

or like this:

services.AddDbContext<StudentManageEntities>(options =>
    options.UseSqlServer(@"Your connection string"));