Ninject - The ninja of. Net Spring. Net - Spring. NET is an open source application framework that makes building enterprise. NET Core applications. Scrutor - Assembly scanning extensions for Microsoft. TinyIoC - An easy to use, hassle free, Inversion of Control Container for small projects, libraries and beginners alike.
Original answer follows. Update I've been using Ninject on my latest project and it has been an absolute pleasure to use. Other IoC screencasts can also be found here on Dimecasts. It depends on what you are looking for, as they each have their pros and cons.
I also found it to be a little bit more complicated than Koin. Dagger is a fully optimized dependency framework for Android using generated code to avoid reflection.
It is maintained by Google and is their recommended solution for doing DI on Android. A Dagger Module is a little bit more verbose than the Modules used in the other frameworks. It uses annotations to describe the classes and wire up the dependencies as follows;.
The constructor of the GreetingServiceImpl also needs to modified to add the Inject annotation for Dagger to declare it as a Singleton. This also needs to be done for the TimeServiceImpl. Note that you use also need to remove the default message for the MessageData class otherwise will complain about multiple constructors. Dagger requires an additional Component class to specify the Modules that will be used in your app.
You also need to define the methods that will inject your classes and a Factory to inject the String into the constructor of the MessageData class. The generated class DaggerComponent is used to start the DI container and is initialized with the Module.
To display the greeting on the screen you need to retrieve the Dagger Component from the Application and inject the Activity with the GreetingService. I checked the Dagger codelab and the recommendation way to test your classes was with mocks without using Dagger. Dagger still requires quite a lot of boilerplate to wire up your dependencies and use it in your app.
It will be a welcome relief when Google addresses these issues and simplifies the syntax. It is a full-featured, runtime based, but reflection-free, implementation of JSR For Toothpick to generate these factories you need to add the InjectConstructor annotation to the class being injected. Alternatively, you can also use the Inject annotation constructor syntax which was used in the Dagger example.
The Module is installed in the root scope when the application starts up. The GreetingService is injected into the Activity using the root scope. Once injected the GreetingService can be used to display the greeting on the screen. This is just a simple study case.
Think of the impact that dependency may have in a more complex scenario with many dependent components. That could really become a huge mess. The last of the SOLID principles proposes a way to mitigate the dependency problem and make it more manageable. This principle is known as the Dependency Inversion Principle and states that:.
You can translate the two formal recommendations as follows: in the typical layered architecture of an application, a high-level component should not directly depend on a lower-level component.
You should create an abstraction for example, an interface and make both components depend on this abstraction. Of course, all of this may seem too abstract.
Well, this article will provide you with examples to clarify the concepts about dependency and the techniques to mitigate it. While the general concepts are valid for any programming language and framework, this article will focus on the.
NET Core framework and will illustrate the infrastructure it provides you to help in reducing component dependency. Before exploring what. NET provides you to fight the dependency disease of your code, it's necessary to put some order in the terminology. You may have heard many terms and concepts about code dependency, and some of them seem to be very similar and may have been confusing.
Well, here is an attempt to give a proper definition of the most common ones:. Dependency Inversion Principle : it's a software design principle; it suggests a solution to the dependency problem but does not say how to implement it or which technique to use. Inversion of Control is the actual mechanism that allows your higher-level components to depend on abstraction rather than the concrete implementation of lower-level components.
Inversion of Control is also known as the Hollywood Principle. This name comes from the Hollywood cinema industry, where, after an audition for an actor role, usually the director says, don't call us, we'll call you. Dependency Injection : this is a design pattern to implement Inversion of Control. It allows you to inject the concrete implementation of a low-level component into a high-level component.
IoC Container : also known as Dependency Injection DI Container, it is a programming framework that provides you with an automatic Dependency Injection of your components.
However, it mostly derives on the type of problem your code is trying to solve. As said above, it is a technique to providing a component with its dependencies, preventing the component itself from instantiating by themselves. You can implement Dependency Injection on your own by creating instances of the lower-level components and passing them to the higher-level ones. You can do it using three common approaches:.
You can implement Dependency Injection manually by using one or more of the three approaches discussed before. Its basic features include:. You will see these features in action in a while. But before this, some basic information is needed. So if for some reason, you want to create your own IoC Container, you should implement this interface.
NET Core, the dependencies managed by the container are called services. You have two types of services:. NET Core heavily relies on it. For example, the Startup class in an ASP. NET application uses Dependency Injection extensively:.
In this example, the Startup constructor requires a configuration parameter implementing the IConfiguration type. Since IConfiguration is one of the framework service types, the IoC Container knows how to create an instance of it and inject it into the Startup class applying the Constructor Injection approach. The same applies to the Configure method. Keep in mind, however, that only the following framework service types can be injected in the Startup constructor and in the Configure method of a standard ASP.
This is a special case for framework services because you don't need to register them. In general, you have to register services needed by your ASP. This method has an IServiceCollection parameter representing the list of services your application depends on.
Practically, the collection represented by this parameter allows you to register a service in the IoC Container. Consider the following example:.
Here, you are registering a dependency for managing authentication for your application. In this specific case, you are using the extension method AddAuthentication with the parameters describing the authentication type you want to use. The framework provides extension methods to register and configure dependencies for the most common services. Autofac implementation of the interfaces in Microsoft.
Abstractions, the. NET Framework dependency injection abstraction. MessagePack for C. Autofac is an IoC container for Microsoft. It manages the dependencies between classes so that applications stay easy to change as they grow in size and complexity.
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