How to use Dagger 2 in an Android app?

Dagger 2 is a powerful dependency injection framework for Java and Android that helps manage your application's dependencies in a clean and efficient way. Here's a basic overview of how to integrate Dagger 2 into your Android app.

Step 1: Add Dagger Dependencies

First, you need to add the Dagger 2 dependencies to your app's build.gradle file:


    dependencies {
        implementation 'com.google.dagger:dagger:2.x' // Replace x with the latest version
        kapt 'com.google.dagger:dagger-compiler:2.x' // For Kotlin projects
    }

Step 2: Create Your Modules

Modules are classes where you define methods that provide dependencies.


    @Module
    class AppModule {
        @Provides
        fun provideContext(application: Application): Context {
            return application.applicationContext
        }
        
        @Provides
        fun provideNetworkService(): NetworkService {
            return NetworkService()
        }
    }

Step 3: Create Your Components

Components are interfaces that connect the modules and the classes that need dependencies.


    @Component(modules = [AppModule::class])
    interface AppComponent {
        fun inject(application: MyApplication)
        fun inject(activity: MainActivity)
    }

Step 4: Initialize Dagger in Your Application Class

Initialize the Dagger component in your Application class:


    class MyApplication : Application() {
        lateinit var appComponent: AppComponent
        
        override fun onCreate() {
            super.onCreate()
            appComponent = DaggerAppComponent.builder()
                .appModule(AppModule())
                .build()
        }
    }

Step 5: Inject Dependencies in Activities or Fragments

Finally, you can inject dependencies into your activities or fragments:


    class MainActivity : AppCompatActivity() {
        @Inject lateinit var networkService: NetworkService
        
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            (application as MyApplication).appComponent.inject(this)
            // Now you can use networkService
        }
    }

How to use Dagger 2 in an Android app?

Step 1: Add Dagger Dependencies

Step 2: Create Your Modules

Step 3: Create Your Components

Step 4: Initialize Dagger in Your Application Class

Step 5: Inject Dependencies in Activities or Fragments

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How to use Dagger 2 in an Android app?

Step 1: Add Dagger Dependencies

Step 2: Create Your Modules

Step 3: Create Your Components

Step 4: Initialize Dagger in Your Application Class

Step 5: Inject Dependencies in Activities or Fragments

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Popular Topics

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