从 AddTransient 到 AddScoped 的 ASP.NET Core 依赖项注入

Question

我正在查看 ASP.NET Core 应用程序中的一些代码，我注意到存储库服务是使用 AddScope 添加的，而在我的中我使用的是 addTransient。我已经查看了差异，但我仍然不明白这将如何改变我的实际应用程序。

这是我正在使用的代码以及我在页面上用于获取/发布操作的服务。

    services.AddHttpContextAccessor();
    services.AddSingleton<IFileProvider>(new PhysicalFileProvider(Path.Combine(Directory.GetCurrentDirectory(), "wwwroot/files")));
    services.AddTransient<IAuthorizationHandler, HasArranqueActivoHandler>();
    services.AddTransient<IAuthorizationHandler, HasArranqueInactivoHandler>();
    services.AddTransient<IAuthorizationHandler, IsParagemNotOnGoingHandler>();
    services.AddTransient<IAuthorizationHandler, IsParagemOnGoingHandler>();


    services.AddTransient<Services.Interfaces.IUserService, Services.UserService>();


        #region AreaProduction
        services.AddTransient<Production.Interfaces.IComponenteService, Production.ComponenteService>();
        services.AddTransient<Production.Interfaces.IReferenciaService, Production.ReferenciaService>();
        services.AddTransient<Production.Interfaces.IProducaoRegistoService, Production.ProducaoRegistoService>();
        services.AddTransient<Production.Interfaces.IParagemService, Production.ParagemService>();
        services.AddTransient<Production.Interfaces.ICelulaService, Production.CelulaService>();
        services.AddTransient<Production.Interfaces.IUapService, Production.UapService>();
        services.AddTransient<Production.Interfaces.ICelulaTipoService, CelulaTipoService>();
        services.AddTransient<Production.Interfaces.IMatrizService, MatrizService>();
        services.AddTransient<Production.Interfaces.IOperadorService, Production.OperadorService>();
        services.AddTransient<Production.Interfaces.IEtiquetaService, Production.EtiquetaService>();
        services.AddTransient<Production.Interfaces.IPokayokeService, Production.PokayokeService>();
        services.AddTransient<Production.Interfaces.IGeometriaService, Production.GeometriaService>();
        services.AddTransient<Production.Interfaces.IEmpregadoService, Production.EmpregadoService>();
        services.AddTransient<Production.Interfaces.IPecaService, Production.PecaService>();
        services.AddTransient<Production.Interfaces.IDefeitoService, Production.DefeitoService>();
        #endregion

        #region AreaRobotics
        services.AddTransient<Robotics.Interfaces.ITurnoService, Robotics.TurnoService>();
        services.AddTransient<Robotics.Interfaces.ICelulaService, Robotics.CelulaService>();
        services.AddTransient<Robotics.Interfaces.ICheckListService, Robotics.CheckListService>();
        services.AddTransient<Robotics.Interfaces.IProducaoService, Robotics.ProducaoService>();
        services.AddTransient<Robotics.Interfaces.IReferenciaService, Robotics.ReferenciaService>();
        services.AddTransient<Robotics.Interfaces.IDefeitoService, Robotics.DefeitoService>();
        services.AddTransient<Robotics.Interfaces.IDefeitoCodigoService, Robotics.DefeitoCodigoService>();
        services.AddTransient<Robotics.Interfaces.IParagemService, Robotics.ParagemService>();
        services.AddTransient<Robotics.Interfaces.IParagemCodigoService, Robotics.ParagemCodigoService>();
        services.AddTransient<Robotics.Interfaces.IPecaService, Robotics.PecaService>();
        services.AddTransient<Robotics.Interfaces.IUapService, Robotics.UapService>();
        services.AddTransient<Robotics.Interfaces.IOperadorService, Robotics.OperadorService>();
        #endregion

    #region AreaRobotics
    services.AddTransient<Areas.Robotics.Services.Interfaces.ITurnoService, Areas.Robotics.Services.TurnoService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.ICelulaService, Areas.Robotics.Services.CelulaService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.ICheckListService, Areas.Robotics.Services.CheckListService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IProducaoService, Areas.Robotics.Services.ProducaoService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IReferenciaService, Areas.Robotics.Services.ReferenciaService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IDefeitoService, Areas.Robotics.Services.DefeitoService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IDefeitoCodigoService, Areas.Robotics.Services.DefeitoCodigoService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IParagemService, Areas.Robotics.Services.ParagemService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IParagemCodigoService, Areas.Robotics.Services.ParagemCodigoService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IPecaService, Areas.Robotics.Services.PecaService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IUapService, Areas.Robotics.Services.UapService>();
    services.AddTransient<Areas.Robotics.Services.Interfaces.IOperadorService, Areas.Robotics.Services.OperadorService>();
    #endregion

我想知道从 AddTransient 更改为 AddScoped 对我的应用程序中的服务有何影响

这是一个简单的创建页面，其中包含许多用于填充选择列表的临时服务

    public class CreateModel : PageModel
    {
        private readonly IMatrizService _matrizService;
        private readonly IReferenciaService _referenciaService;
        private readonly IUapService _uapService;
        private readonly ICelulaTipoService _celulaTipoService;
        private readonly ICelulaService _celulaService;
        private readonly IToastNotification _toastNotification;
        private readonly ILogger<CreateModel> _logger;

        public CreateModel(IToastNotification toastNotification, 
                           ICelulaTipoService celulaTipoService,
                           ICelulaService celulaService,
                           IUapService uapService,
                           IReferenciaService referenciaService,
                           IMatrizService matrizService,
                           ILogger<CreateModel> logger)
        {
            _matrizService = matrizService;
            _referenciaService = referenciaService;
            _uapService = uapService;
            _celulaTipoService = celulaTipoService;
            _celulaService = celulaService;
            _toastNotification = toastNotification;
            _logger = logger;
        }

        [BindProperty]
        public Matriz Matriz { get; set; }

        public void OnGet()
        {
            ViewData["CelulaId"] = new SelectList(_celulaService.GetAllFromCache(), "Id", "Nome");
            ViewData["UAPId"] = new SelectList(_uapService.GetAllFromCache(), "Id", "Nome");
            ViewData["ReferenciaId"] = new SelectList(_referenciaService.GetAllFromCache(), "Id", "Nome");
        }

        public async Task<IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                ViewData["CelulaId"] = new SelectList(_celulaService.GetAllFromCache(), "Id", "Nome");
                ViewData["UAPId"] = new SelectList(_uapService.GetAllFromCache(), "Id", "Nome");
                ViewData["ReferenciaId"] = new SelectList(_referenciaService.GetAllFromCache(), "Id", "Nome");

                _toastNotification.AddErrorToastMessage("Falha ao criar Matriz. Verifique os dados novamente.");

                return Page();
            }

            _matrizService.Add(Matriz);

            try
            {
                await _matrizService.SaveChangesAsync();
            }
            catch (DbUpdateException e)
            {
                //This either returns a error string, or null if it can’t handle that error
                _logger.LogError($@"Falha ao Adicionar Referência
                                    Area: Administration
                                    Page: Account/Robotics/Referencias/Create
                                    Error: {e.InnerException}");

                _toastNotification.AddErrorToastMessage($"A Matriz com a Referência {Matriz.Referencia.Nome} já existe");

                return Page();
            }

            _toastNotification.AddSuccessToastMessage("Matriz criada com sucesso.");

            return RedirectToPage("./Index");
        }
    }

我的大部分服务通常与 crud 方法相同

  public interface IUserService
    {
        IQueryable<User> GetAll();
        User GetById(int id);
        void Add(User user);
        void Update(User user);
        int AddAndSave(User user);
        int SaveChanges();
        int UpdateDateAndSave(User user);
        User GetByUsername(string username);
    }

public class UserService : IUserService
{
    private readonly DatabaseContext _context;

    public UserService(DatabaseContext context)
    {
        _context = context;
    }

    public void Add(User user)
    {
        _context.Users.Add(user);
    }

    public int AddAndSave(User user)
    {
        _context.Users.Add(user);
        return _context.SaveChanges();
    }

    public IQueryable<User> GetAll()
    {
        return _context.Users.AsNoTracking();
    }

    public User GetById(int id)
    {
        return _context.Users.Find(id);
    }

    public User GetByUsername(string username)
    {
        return _context.Users
            .Include(u => u.Colaborador)
            .Include(u => u.UserRoles)
            .ThenInclude(ur => ur.Role)
            .AsNoTracking()
            .FirstOrDefault(u => u.Username == username);
    }

    public int SaveChanges()
    {
        return _context.SaveChanges();
    }

    public void Update(User user)
    {
        _context.Users.Update(user);
    }

    public int UpdateDateAndSave(User user)
    {
         user.DataSessao = DateTime.Now;
        _context.Users.Attach(user);
        _context.Entry(user).Property(u => u.DataSessao).IsModified = true;
        return _context.SaveChanges();

    }
}

Answer 1

如果我开始将 AddScoped 用于服务，这将如何影响我的整个应用程序

我们必须查看一项服务（或者实际上是所有服务）才能确定。

但很可能这无关紧要。

需要注意的是服务中的状态。通常没有状态，然后 Scoped 或 Transient 无关紧要。

那么，您的任何服务实现是否有字段（注入服务除外）？

当它们当前注册为 Transient 时，它们很可能是无状态的。这使得对 Scoped 的更改是安全的，但仍然没有必要。

换一种方式（从 Scoped 到 Transient）需要更多的调查。