DI error

 

🔥 Why This Happens

You likely did ONE of these:

• Registered IErrorLoggerService as Scoped, but you're calling it from:

  • Middleware constructor

  • A static class

  • A background task

  • Something running outside the HTTP request pipeline

  • Inside Program.cs directly during startup

OR

• You forgot to register it in DI.

---

💯 THE FIX: Register the service + Use it correctly in middleware

---

✅ 1. Register your IErrorLoggerService properly

In Program.cs or ServiceExtensions:

builder.Services.AddScoped<IErrorLoggerService, ErrorLoggerService>();

---

✅ 2. DO NOT inject scoped services into middleware constructors

Middleware constructor runs once at startup = singleton scope
Scoped services = per request → mismatch

❌ Bad:

public class ExceptionHandlingMiddleware
{
    private readonly IErrorLoggerService _errorLogger; // ❌ scoped injected into singleton
}

This is EXACTLY what triggers your error.

---

✅ 3. Proper way → Resolve inside InvokeAsync using context.RequestServices

Modify your middleware like this:

public async Task InvokeAsync(HttpContext context)
{
    try
    {
        await _next(context);
    }
    catch (Exception ex)
    {
        // Resolve scoped service here
        var loggerService = context.RequestServices.GetRequiredService<IErrorLoggerService>();

        await loggerService.LogErrorAsync(new ErrorLogDto
        {
            UserName = context.User?.Identity?.Name ?? "SYSTEM",
            ErrorMessage = ex.Message,
            ErrorProcedure = context.Request.Path,
            ErrorDateTime = DateTime.UtcNow
        });

        throw; // continue normal exception behavior
    }
}

This is safe because middleware resolves the scoped service per request.

---

🎉 This removes the error completely.

---

⭐ Bonus: Template for IErrorLoggerService

public interface IErrorLoggerService
{
    Task LogErrorAsync(ErrorLogDto dto);
}

Implementation:

public class ErrorLoggerService : IErrorLoggerService
{
    private readonly UARDbContext _context;

    public ErrorLoggerService(UARDbContext context)
    {
        _context = context;
    }

    public async Task LogErrorAsync(ErrorLogDto dto)
    {
        var error = new TblErrors
        {
            UserName = dto.UserName,
            ErrorMessage = dto.ErrorMessage,
            ErrorProcedure = dto.ErrorProcedure,
            ErrorDateTime = DateTime.UtcNow
        };

        await _context.TblErrors.AddAsync(error);
        await _context.SaveChangesAsync();
    }
}