Dependency injection (DI) is a design pattern that promotes loose coupling by providing dependencies to objects instead of having them create their own. It simplifies code, enhances testability, and improves maintainability.
In Android applications, DI frameworks like Dagger can be used for implementing dependency injection. Dagger generates code at compile-time, ensuring efficient performance. To implement DI using Dagger:
1. Add Dagger dependencies in the build.gradle file.
2. Create interfaces annotated with @Module to define how dependencies are provided.
3. Use @Provides annotation within modules to specify methods responsible for creating instances.
4. Annotate components with @Component, linking modules to classes requiring dependencies.
5. In classes needing dependencies, use @Inject annotation on constructors or fields.
6. Build the project, allowing Dagger to generate implementation classes.
7. Initialize the generated component in the application class or activity, injecting required dependencies.
Other DI frameworks include Koin and Hilt. Koin uses a DSL-based approach, while Hilt extends Dagger, simplifying its usage specifically for Android projects.
