online test in asp.net core api and angular

    [Route("api/[controller]")]
    [ApiController]
    public class QuizzController : ControllerBase
    {
        private readonly ApplicationDbContext _context;
        public QuizzController(ApplicationDbContext context)
        {
            _context = context;
        }
        // ===============================
        // CLAIM HELPERS (FAST)
        // ===============================
        private string CurrentUserName =>
            User.Identity?.Name ?? "System";
        private int CurrentDepartmentId =>
            int.TryParse(
                User.FindFirstValue("DepartmentId"),
                out var id)
            ? id
            : 0;
        // List all available tests
        public async Task Index()
        {
            var tests = await _context.Tests.ToListAsync();
            return Ok(tests);
        } //Maybe this action result needs @model IEnumerable
        //public IActionResult QuizList()
        //{
        //   var quiz = _context.Questions.Include(x => x.Answers)
        //       .Select(q => new
        //       {
        //           QuestionText = q.Text,
        //           Answers = q.Answers.Select(a => new SelectListItem(a.Text, a.Id.ToString())).ToList()
        //        }).ToList();
        //    return View(quiz);
        //}
        // Show quiz by TestId
        public async Task Take(int id)
        {
            var test = await _context.Tests
                .Include(x => x.Questions)
                    .ThenInclude(x => x.Answers)
                .FirstOrDefaultAsync(x => x.Id == id);
            if (test == null)
                return NotFound();
            return Ok(test);
        }
        // Handle quiz submission and store attempt 
        [HttpPost]
        public async Task Submit(int testId, int[] selectedOptions)
        {
            var questions = await _context.Question
                .Include(q => q.Answers)
                .Where(q => q.TestId == testId)
                .ToListAsync();
            int score = 0;
            var attempt = new TestAttempt
            {
                UserId = CurrentUserName,
                TestId = testId,
                AttemptDate = DateTime.UtcNow
            };
            foreach (var question in questions)
            {
                var correctOption = question.Answers.FirstOrDefault(o => o.IsCorrect);
                var selectedOptionId = selectedOptions.FirstOrDefault(o => question.Answers.Any(opt => opt.Id == o));
                bool isCorrect = correctOption != null && selectedOptionId == correctOption.Id;
                if (isCorrect) score++;
                attempt.Answers.Add(new UserAnswer
                {
                    QuestionId = question.Id,
                    AnswerId = selectedOptionId,
                    IsCorrect = isCorrect
                });
            }
            attempt.Score = score;
            attempt.IsPassed = score >= questions.Count / 2; // replace with your real pass threshold
            _context.TestsAttempt.Add(attempt);
            await _context.SaveChangesAsync();
            return RedirectToAction("History", new { userId = CurrentUserName });
        }
        // Show attempt history for a user
        public async Task History()
        {
            var attempts = await _context.TestsAttempt
                .Include(a => a.Test)
                .Where(a => a.UserId == CurrentUserName)
                .OrderByDescending(a => a.AttemptDate)
                .ToListAsync();
            return Ok(attempts);
        }
        public async Task Details(int id)
        {
            var attempt = await _context.TestsAttempt
                .Include(a => a.Test)
                .Include(a => a.Answers)
                    .ThenInclude(ua => ua.Question)
                        .ThenInclude(q => q.Answers)
                .Include(a => a.Answers)
                    .ThenInclude(ua => ua.Answer)
                .FirstOrDefaultAsync(a => a.Id == id);
            if (attempt == null)
                return NotFound();
            return Ok(attempt);
        }
    } I want  populate test in angular where users can take, submit  tests, and see their  scores

Yes, you can handle the complete flow with Angular + ASP.NET Core Web API. The API should return JSON rather than MVC redirects/views.

A simple approach is:

Tests API → Angular test list → Take test → Submit answers → Return score → Show history

A few changes are needed in your controller. For example, use ActionResult/IActionResult:

[HttpGet]
public async Task Index()
{
    var tests = await _context.Tests.ToListAsync();
    return Ok(tests);
}

[HttpGet("{id}")]
public async Task Take(int id)
{
    var test = await _context.Tests
        .Include(x => x.Questions)
        .ThenInclude(x => x.Answers)
        .FirstOrDefaultAsync(x => x.Id == id);

    if (test == null)
        return NotFound();

    return Ok(test);
}

For submission, I'd recommend sending a request model from Angular instead of using int[] selectedOptions:

public class SubmitTestRequest
{
    public int TestId { get; set; }
    public List SelectedAnswerIds { get; set; } = new();
}

Then your API can return the result directly:

return Ok(new
{
    Score = score,
    TotalQuestions = questions.Count,
    IsPassed = attempt.IsPassed
});

In Angular, you can then have:

getTests() {
  return this.http.get('/api/quizz');
}

getTest(id: number) {
  return this.http.get(`/api/quizz/${id}`);
}

submitTest(data: any) {
  return this.http.post('/api/quizz/submit', data);
}

getHistory() {
  return this.http.get('/api/quizz/history');
}

The Angular screens could be kept simple:

Test List – display available tests with a Take Test button.
Take Test – display questions and answer options using radio buttons.
Submit Test – send the selected answers to the API.
Result – show score, total questions, and pass/fail status.
My History – show previous attempts and scores.

One important point: don't send IsCorrect to Angular or trust the submitted score. The correct answers should remain on the server, and the API should calculate the score during submission. This prevents users from manipulating the result.

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Niharika Gupta8d ago
Yes, you can handle the complete flow with Angular + ASP.NET Core Web API. The API should return JSON rather than MVC redirects/views.
A simple approach is:
Tests API → Angular test list → Take test → Submit answers → Return score → Show history
A few changes are needed in your controller. For example, use ActionResult/IActionResult:
```
[HttpGet]
public async Task Index()
{
    var tests = await _context.Tests.ToListAsync();
    return Ok(tests);
}

[HttpGet("{id}")]
public async Task Take(int id)
{
    var test = await _context.Tests
        .Include(x => x.Questions)
        .ThenInclude(x => x.Answers)
        .FirstOrDefaultAsync(x => x.Id == id);

    if (test == null)
        return NotFound();

    return Ok(test);
}
```
For submission, I'd recommend sending a request model from Angular instead of using int[] selectedOptions:
```
public class SubmitTestRequest
{
    public int TestId { get; set; }
    public List SelectedAnswerIds { get; set; } = new();
}
```
Then your API can return the result directly:
```
return Ok(new
{
    Score = score,
    TotalQuestions = questions.Count,
    IsPassed = attempt.IsPassed
});
```
In Angular, you can then have:
```
getTests() {
  return this.http.get('/api/quizz');
}

getTest(id: number) {
  return this.http.get(`/api/quizz/${id}`);
}

submitTest(data: any) {
  return this.http.post('/api/quizz/submit', data);
}

getHistory() {
  return this.http.get('/api/quizz/history');
}
```
The Angular screens could be kept simple:
1. Test List – display available tests with a Take Test button.
2. Take Test – display questions and answer options using radio buttons.
3. Submit Test – send the selected answers to the API.
4. Result – show score, total questions, and pass/fail status.
5. My History – show previous attempts and scores.
One important point: don't send IsCorrect to Angular or trust the submitted score. The correct answers should remain on the server, and the API should calculate the score during submission. This prevents users from manipulating the result.
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