How to implement Dagger for worker classes in Dagger 2.16 ?('android.arch.work:work-runtime')

问题

How to implement Dagger for worker classes in Dagger 2.16?

public class SyncWorker extends  Worker {

    @Inject
    ISettingRepository settingRepository;

    @NonNull
    @Override
    public Result doWork() {

        sync();
        return Result.SUCCESS;
    }

    private void sync() {

    }
}

my AppComponent

@Singleton
@Component(modules = {
        AndroidSupportInjectionModule.class,
        BaseModule.class,
        ApiModule.class,
        UserDatabaseModule.class,
        SaleDatabaseModule.class,
        AppModule.class,
        ActivityBuilderModule.class
})
public interface AppComponent extends AndroidInjector<DaggerApplication> {
    void inject(BaseApp app);

    @Override
    void inject(DaggerApplication application);

    @Component.Builder
    interface Builder {
        @BindsInstance

        Builder getApp(Application application);

        AppComponent build();
    }

}

How can I inject the settingRepository?

回答1:

I was able to inject a worker with this approach.

First, create a new method inside your app component that will inject your worker class.

@Singleton
public interface AppComponent extends AndroidInjector<YourApplicationClass> {

    @Component.Builder
    interface Builder {

        @BindsInstance
        AppComponent.Builder application(Application application);

        AppComponent build();
    }

    void inject(NotifWorker worker);
}

Inside your application, build your dagger component as usual but assign it to a variable and make it global.

public class YourApplicationClass implements HasActivityInjector {

  private AppComponent appComponent;
  @Override
  public void onCreate() {
      super.onCreate();

      appComponent = DaggerAppComponent.builder()
              .application(this)
              .build();

      appComponent.inject(this);
  }

  public AppComponent getAppComponent() {
      return appComponent;
  }
}

Inside your worker class, do something like this.

public class NotifWorker extends Worker {

  @Inject
  ToBeInjectedClass toBeInjectedClass;

  public NotifWorker() {
    YourApplicationClass
        .getInstance()
        .getAppComponent()
        .inject(this)
  }
}

回答2:

To inject any classes in Dagger 2, you have to first provide those classes using @provides annotation in the module.

You have to first create a component containing a module which provides the desired class.

Example:-

@component(modules = {Module1.class})
public interface Component1{

void inject(SyncWorker syncWorker);
}

@Module
public class Module1{

@Provides
public ISettingRepository getSettingRepo(){
  return new ISettingRepository();
}

}

Now write in your code, a constructor that is used to inject the component into your worker class.

public class SyncWorker extends  Worker {

    @Inject
    ISettingRepository settingRepository;

    public SyncWorker(){
       DaggerComponent1.builder().build().inject(this);
     }

    @NonNull
    @Override
    public Result doWork() {

        sync();
        return Result.SUCCESS;
    }

    private void sync() {

    }
}

Now when the constructor runs, your settingRepository instance would be initialized.

来源：https://stackoverflow.com/questions/51279541/how-to-implement-dagger-for-worker-classes-in-dagger-2-16-android-arch-workw

标签

java

android

dependency-injection

dagger-2

android-workmanager