#Circular studio windows code

The approach I actually use in this situation takes advantage of the Lazy class.Still looking for the best context menu editors, Fast Explorer can be a good pick for you.

#Circular studio windows code

You have to scan the code of the class to find them. Instead of having them all clearly declared at the constructor level, you now have just an IServiceProvider which doesn’t tell you anything about the actual dependencies. It hides the dependencies of your class.This is bad, because your class shouldn’t have to know anything about the injection dependency mechanism being used after all, the app could be using Pure DI, i.e.

It makes your class depend explicitly on the service provider.

However, I don’t really like this approach, because it smells of the Service Locator pattern, which is a known anti-pattern. Private readonly IServiceProvider _services īecause it’s no longer necessary to resolve IA while C is being constructed, the cycle is broken (at least during construction), and the problem fixed. For instance, the C class I mentioned earlier might initially look like this: One way to do that is to inject the IServiceProvider into your class, and use services.GetRequiredService() when you need to use T. resolve it at the last possible moment, when you actually need to use it. The trick is to resolve one of the dependencies in the cycle lazily, i.e. Because of deadlines, you might not have the time to refactor your code and thoroughly test it for regressions.įortunately, if you’re willing to incur a bit of technical debt, there’s a simple workaround that works in most cases (what I referred to as “cheating” earlier). While, ideally, you would opt for a refactoring, it’s not always practical. So you’re faced with a choice: refactor a significant part of your app to avoid the dependency cycle, or “cheat”. One day, you innocently add a dependency to a service, and things blow up in your face.

However, when a real-world app reaches a certain level of complexity, it can sometimes be difficult to avoid. So, clearly, this situation should be avoided. System.InvalidOperationException: A circular dependency was detected for the service of type ‘Demo.IA’. NET Core’s built-in IoC container detects this, and throws a helpful exception: The resolution of IA will cannot complete in fact. When you try to resolve IA, the dependency injection container will try to create an instance of A to do that, it will need to resolve IB, so it will try to create an instance of B to do that, it will need to resolve IC, so it will try to create an instance of C and to do that, it will need to resolve IA… which was already being resolved. C, which implements interface IC and depends on IA.B, which implements interface IB and depends on IC.

A, which implements interface IA and depends on IB.For instance, if you have these components: If you accidentally introduce a circular dependency in an NET Core app that uses dependency injection, you will know immediately, because the resolution of a component involved in the dependency cycle will fail. It is generally agreed that this should be avoided I won’t go into the details of the conceptual and theoretical reasons, because there are plenty of resources about it on the web.īut circular dependencies also have a very concrete effect.

A depends on B which depends on C which depends on A: A circular dependency is when some components depend on each other, directly or indirectly, e.g. When building an application, good design dictates that you should avoid circular dependencies between your services.