如果我在Asp.Net Core 2.0 Web应用程序中创建一个BaseController来封装一些常见的依赖关系，那么在实际的 Controller 中它们仍然是必需的。
例如，默认MVC 6 Web应用程序中的标准“帐户”和“管理” Controller 。
public class AccountController : Controller
{
private readonly UserManager<ApplicationUser> _userManager;
private readonly SignInManager<ApplicationUser> _signInManager;
private readonly IEmailSender _emailSender;
private readonly ILogger _logger;
public AccountController(
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
IEmailSender emailSender,
ILogger<AccountController> logger)
{
_userManager = userManager;
_signInManager = signInManager;
_emailSender = emailSender;
_logger = logger;
}
//rest of code removed
}
public class ManageController : Controller
{
private readonly UserManager<ApplicationUser> _userManager;
private readonly SignInManager<ApplicationUser> _signInManager;
private readonly IEmailSender _emailSender;
private readonly ILogger _logger;
private readonly UrlEncoder _urlEncoder;
private const string AuthenicatorUriFormat = "otpauth://totp/{0}:{1}?secret={2}&issuer={0}&digits=6";
public ManageController(
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
IEmailSender emailSender,
ILogger<ManageController> logger,
UrlEncoder urlEncoder)
{
_userManager = userManager;
_signInManager = signInManager;
_emailSender = emailSender;
_logger = logger;
_urlEncoder = urlEncoder;
}
// rest of code removed
}
在我正在构建的定制Web应用程序模板中，我将帐户 Controller 重构为三个不同的 Controller ，RegisterController(负责处理与用户注册有关的所有内容)，LoginController(处理登录和注销)，以及余额中的三分之一。我将Manage Controller一分为二，一个ManagePasswordController(与密码有关的所有内容)和一个UserManageController(与其他所有内容有关的内容)。
每个DI要求都有很多共同点，我想将它们放在BaseController中。看起来像这样吗？
public abstract class BaseController : Controller
{
private readonly IConfiguration _config;
private readonly IEmailSender _emailSender;
private readonly ILogger _logger;
private readonly SignInManager<ApplicationUser> _signInManager;
private readonly UserManager<ApplicationUser> _userManager;
protected BaseController(IConfiguration iconfiguration,
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
IEmailSender emailSender,
ILogger<ManageController> logger)
{
_config = iconfiguration;
_userManager = userManager;
_signInManager = signInManager;
_emailSender = emailSender;
_logger = logger;
}
//rest of code removed
}
但这似乎无济于事？因为在我看来，我仍然必须注入(inject)一切。我不能说对(我是DI的新手，所以显然不知道)，但是BaseController应该允许我做在BaseController和RegisterController之间不常见的DI。我错了吗？我该如何完成我想做的事情？
public class RegisterController : BaseController
{
private const string ConfirmedRegistration = "User created a new account with password.";
private readonly UserManager<ApplicationUser> _userManager;
private readonly SignInManager<ApplicationUser> _signInManager;
private readonly IEmailSender _emailSender;
private readonly ILogger _logger;
private readonly IConfiguration _config;
public RegisterController(
IConfiguration config,
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
IEmailSender emailSender,
ILogger<AccountController> logger) : base(config, userManager, signInManager, emailSender, logger)
{
_userManager = userManager;
_signInManager = signInManager;
_emailSender = emailSender;
_logger = logger;
_config = config;
}
//rest of code removed
}
更新
根据鲁弗爵士的建议
public abstract class BaseController : Controller
{
protected UserManager<ApplicationUser> UserManager { get; }
protected SignInManager<ApplicationUser> SignInManager { get; }
protected IConfiguration Config { get; }
protected IEmailSender EmailSender { get; }
protected ILogger AppLogger { get; }
protected BaseController(IConfiguration iconfiguration,
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
IEmailSender emailSender,
ILogger<ManageController> logger)
{
AppLogger = logger;
EmailSender = emailSender;
Config = iconfiguration;
SignInManager = signInManager;
UserManager = userManager;
}
}
和继承 Controller
public class TestBaseController : BaseController
{
public TestBaseController() : base()
{
}
}
这行不通。 Resharper告诉我必须在TestBaseController构造函数的基本构造函数调用中添加参数。
还应该从.Net Core 2.0中的Controller或ControllerBase继承BaseController吗？
最佳答案
有very few good reasons to use a BaseController in MVC。在这种情况下，基本 Controller 仅添加要维护的更多代码，没有任何实际好处。
对于真正的cross-cutting concerns，在MVC中处理它们的最常用方法是使用global filters，尽管MVC内核中有一些值得考虑的新选项。
但是，您的问题看起来像跨 Realm 的关注，而不是违反Single Responsibility Principle。也就是说，具有3个以上的注入(inject)依赖项是您的 Controller 做得太多的代码味道。最实用的解决方案是Refactor to Aggregate Services。
在这种情况下，我认为您需要至少有1个需要显式的隐式服务-即UserManager和SignInManager应该包装成自己的服务。从那里，您可能会将其他3个依赖项注入(inject)到该服务中(当然，取决于它们的使用方式)。因此，您可能会将其降低为AccountController和ManageController的单个依赖项。
一些迹象表明 Controller 做得太多:
在这种情况下，值得一看的是，您是否可以将该逻辑移至其自己的服务中，并将任何共享逻辑移至该服务的依赖项中，等等。