Dependency injection (DI) frameworks resolve dependencies by maintaining a registry of components and their dependencies. When a client requests a dependency, the DI framework retrieves the component from the registry and provides it to the client. The specific steps involved in resolving dependencies vary depending on the DI framework, but the general process is as follows:
- Component Registration: Developers register components with the DI framework. This typically involves providing the component type and its dependencies.
- Dependency Graph Construction: The DI framework constructs a dependency graph, which represents the relationships between components and their dependencies. This graph is used to determine how to resolve dependencies when they are requested.
- Dependency Resolution: When a client requests a dependency, the DI framework traverses the dependency graph to determine the necessary components and constructs them if necessary. It then provides the requested component to the client.
DI frameworks typically support different strategies for resolving dependencies, such as:
- Constructor Injection: Dependencies are passed to a component's constructor.
- Method Injection: Dependencies are passed to a component's methods.
- Property Injection: Dependencies are set on a component's properties.
- Lifetime Management: DI frameworks often provide mechanisms for managing the lifetime of components. This includes creating, using, and disposing of components as needed.
