背景
在Web应用程序中,我创建存储过程,然后创建edmx文件以使用存储过程来处理所有数据库交互。
但是我开始怀疑我是否做对了,因为,如您在下面的示例中所见,
即使在被调用方法不需要数据库工作的情况下,每次Context
被调用时,我都实例化Controller
的两个实例
我要在每个存储库中实例化一个Context
的实例,因此当一个请求需要从存储库A和B中获取数据时,我有两个Context
的实例。
存储库A
public class RepositoryA
{
private readonly Context _context;
public RepositoryA()
{
_context = new Context();
}
public List<CLASS> GetA(int id)
{
return _context.GetByID(id);
}
}
存储库B
public class RepositoryB
{
private readonly Context _context;
public RepositoryB()
{
_context = new Context();
}
public List<CLASS> GetB(int id)
{
return _context.GetByID(id);
}
}
控制器
public class Controller
{
private readonly IRepositoryA _reposA;
private readonly IRepositoryB _reposB;
public Controller() : this(new RepositoryA(), new RepositoryB())
{}
public Controller(IRepositoryA a, IRepositoryB b)
{
_respoA = a;
_reposB = b;
}
public ActionResult METHOD()
{
//do something with both RepositoryA and RepositoryB
var dataFromA = _reposA.GetA(ID);
var dataFromB = _reposB.GetB(ID);
return View(someData);
}
}
现在的问题是:我不确定这是否应该是正常的实现,因此我一直在尝试找出如何以更有效和可测试的方式进行设置,并且尝试了类似的方法这个。
我相信这种设计解决了我的一些担忧:
每次调用Controller时都会调用服务,但是不会每次都实例化Context(每个请求都实例化Context)。
当服务同时需要存储库A和存储库B时,它将使用相同的上下文
但是,在Service
的设置方式下,我无法使用测试数据对Service
进行单元测试,因为无法使用模拟存储库。
public class Controller
{
private Service _service;
public Controller()
{
_service = new Service();
}
public ActionResult METHOD()
{
_service.DoSomethingWithRepoAandB();
return View();
}
}
public class Service
{
public void DoSomethingWithRepoAandB()
{
using (var _context = new Context())
{
RepositoryA a = new RepositoryA(_context);
RepositoryB b = new RepositoryB(_context);
something = a.DoSomethingWithA();
otherThing = b.DoOtherThingWithB();
}
}
}
所以,我认为我应该像这样设置Service
。
通过这种设计,每次调用Context
时都会实例化Controller
(除非我在Service
方法中实例化Controller
),但是我可以通过传递来进行单元测试模拟存储库。
public class Service
{
private readonly Context _context;
private IRepositoryA _a;
private IRepositoryB _b;
public Service()
{
_context = new Context();
_a = new RepositoryA(_context);
_b = new RepositoryB(_context);
}
// Pass Mock Repositories in unit tests
public Service(RepositoryA a, RepositoryB b)
{
_a = a;
_b = b;
}
public void DoSomethingWithRepoAandB()
{
something = _a.DoSomethingWithA();
otherThing =_b.DoOtherThingWithB();
}
}
我这样做是完全错误还是在正确的轨道上?我将不胜感激。
答案 0 :(得分:-1)
您的服务不应包含有关您的上下文的任何信息,这些信息只能由存储库遵循SOLID原则访问。
您的图层访问应如下:
控制器->服务->存储库->上下文
在IRepository接口上,您将拥有要调用的方法,并且可以手动实例化它们,但是要正确实现,必须设置依赖项注入。
此外,您的存储库构造函数不会接收任何上下文作为参数,因此您无法执行以下操作:
RepositoryA a = new RepositoryA(_context);
另一方面,您的控制器也不应访问存储库,因为它会破坏您的体系结构
public ActionResult METHOD()
{
//do something with both RepositoryA and RepositoryB
var dataFromA = _reposA.GetA(ID);
var dataFromB = _reposB.GetB(ID);
return View(someData);
}
这是正确的代码,需要进一步了解:
public class RepositoryA : IRepositoryA
{
private readonly Context _context;
public RepositoryA(Context context)
{
_context = context;
}
public List<CLASS> GetA(int id)
{
return _context.GetByID(id);
}
}
public interface IRepositoryA
{
List<CLASS> GetA(int id);
}
public class RepositoryB : IRepositoryB
{
private readonly Context _context;
public RepositoryB(Context context)
{
_context = context;
}
public List<CLASS> GetB(int id)
{
return _context.GetByID(id);
}
}
public interface IRepositoryB
{
List<CLASS> GetB(int id);
}
public class Controller
{
private IService _service;
public Controller(IService service)
{
_service = service;
}
public ActionResult METHOD(int id)
{
//do something with both RepositoryA and RepositoryB THROUGH the service. The service needs to hold the business rules, and repositories should only care about querying data and handling contexts.
var data = _service.DoSomethingWithRepoAandB(id)
return View(data);
}
}
public class Service : IService
{
private IRepositoryA _a;
private IRepositoryB _b;
// Pass Mock Repositories in unit tests -> PS: You can't have 2 constructors if you're using dependency injection.
public Service(RepositoryA a, RepositoryB b)
{
_a = a;
_b = b;
}
public void DoSomethingWithRepoAandB(int id)
{
var something = _a.GetA(id);
var otherThing = _b.GetB(id);
}
}
public interface IService
{
void DoSomethingWithRepoAandB(int id);
}
public class Bootstrapper
{
//this class should be in a separated assembly, responsible for handling the dependency injection. Using Simple Injection syntax just as an example
public static void RegisterServices(Container container) //IoC Container
{
container.Register<IService, Service>(Lifestyle.Scoped);
container.Register<IRepositoryA, RepositoryA>(Lifestyle.Scoped);
container.Register<IRepositoryB, RepositoryB>(Lifestyle.Scoped);
container.Register<Context>(() => {
var options = // Configure your ContextOptions here
return new Context(options);
});
}
}
public class Startup
{
//This is your startup configuration if you're using WebApi. If you're on MVC, you can do this on your Global.asax
public void Configuration()
{
var container = new Container();
container.Options.DefaultScopedLifestyle = new AsyncScopedLifestyle();
BootStrapper.RegisterServices(container);
}
}