Register and Resolve Types in Unity Container in C# .NET

Register and Resolve Types in Unity Container in C# .NET

1. Introduction Unity Container is a powerful dependency injection container provided by Microsoft for managing object dependencies in C# .NET applications. It enables developers to register and resolve types, allowing for loose coupling, modular design, and easier testing. This documentation will guide you through the process of registering and resolving types using Unity Container.

2. Installation To use Unity Container in your C# .NET project, you need to install the appropriate NuGet package. Open the NuGet Package Manager Console and execute the following command:

csharp
Install-Package Unity

3. Registering Types In Unity Container, you register types along with their corresponding interfaces or base classes. There are various ways to register types, as described below:

3.1. Registering with Interface

csharp
IUnityContainer container = new UnityContainer();
container.RegisterType<IService, MyService>();

In this example, we register the MyService class with the IService interface. This allows us to resolve instances of IService using the registered implementation MyService.

3.2. Registering with Base Class

csharp
IUnityContainer container = new UnityContainer();
container.RegisterType<BaseClass, DerivedClass>();

Here, we register the DerivedClass with its base class BaseClass. Now, we can resolve instances of BaseClass using the registered implementation DerivedClass.

3.3. Registering with Named Mapping

csharp
IUnityContainer container = new UnityContainer();
container.RegisterType<IService, MyService>("Service1");
container.RegisterType<IService, AnotherService>("Service2");

In this example, we register two different implementations (MyService and AnotherService) for the same interface IService, but with different names ("Service1" and "Service2"). This allows us to resolve instances based on their names.

4. Resolving Types After registering types with Unity Container, we can resolve them to obtain instances whenever needed. Here's how to resolve types:

4.1. Resolving by Type

csharp
IUnityContainer container = new UnityContainer();
container.RegisterType<IService, MyService>();
IService service = container.Resolve<IService>();

In this code snippet, we resolve the IService interface and assign the resolved instance to the service variable. Unity Container automatically creates an instance of MyService and resolves it for us.

4.2. Resolving by Name

csharp
IUnityContainer container = new UnityContainer();
container.RegisterType<IService, MyService>("Service1");
container.RegisterType<IService, AnotherService>("Service2");
IService service = container.Resolve<IService>("Service2");

Here, we resolve the IService interface using the name "Service2". Unity Container finds the registered implementation AnotherService associated with "Service2" and resolves it.

5. Conclusion Unity Container simplifies the process of registering and resolving types in C# .NET applications. It promotes loose coupling and modular design, making your code more maintainable and testable. By following the guidelines provided in this documentation, you can effectively utilize Unity Container to manage dependencies in your projects.

This documentation provides a brief overview of registering and resolving types in Unity Container. For more advanced scenarios and additional features, please refer to the Unity Container documentation and resources available at https://github.com/unitycontainer/unity.