Question

匕首模块

@Module
public class NetModule {

    @Provides
    @Singleton
    Gson provideGson() {
        GsonBuilder gsonBuilder = new GsonBuilder();
        return gsonBuilder.create();
    }

    @Provides
    @Singleton
    OkHttpClient provideOkHttpClient() {
        OkHttpClient client = new OkHttpClient();
        return client;
    }

    @Provides
    @Singleton
    Retrofit provideRetrofit(Gson gson, OkHttpClient okHttpClient) {
        Retrofit retrofit = new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create(gson))
                .baseUrl(BuildConfig.SERVER_BASE_URL)
                .client(okHttpClient)
                .build();
        return retrofit;
    }
}

@Module
public class AppModule{

    private Application application;

    public AppModule(Application application){
        this.application = application;
    }

    @Provides
    @Singleton
    Application provideApplication() {
        return application;
    }
}

@Module
public class ImageModule {

    @Provides
    @Singleton
    Picasso providePicasso(Application application, OkHttpClient client) {
        Picasso.Builder builder = new Picasso.Builder(application);
        builder.downloader(new OkHttp3Downloader(client));
        return builder.build();
    }

}

这些是组件

@Singleton
@Component(modules={NetModule.class})
public interface NetComponent {

    void inject(MyFragment fragment);
}

@Singleton
@Component(modules={AppModule.class, ImageModule.class}, dependencies = {NetModule.class})
public interface ImageComponent {

    void inject(MyFragment fragment);
}

这就是我注册组件的方式

public class MyApp extends Application{

    @Override
    public void onCreate() {

        netComponent = DaggerNetComponent.builder()
                .netModule(new NetModule())
                .build();

        imageComponent = DaggerImageComponent.builder()
                .appModule(new appModule(this))
                .imageModule(new ImageModule())
                .build();

    }

}

在片段中

public class MyFragment extends Fragment {

   @Inject
   Retrofit retrofit;

   @Inject
   Picasso picasso;

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,   
     Bundle savedInstanceState) {

   ((MyApp)getActivity().getApplication()).getNetComponent().inject(this);

   ((MyApp)getActivity().getApplication()).getImageComponent().inject(this);
  ....

  }


}

我收到编译错误如下

错误：（25,10）错误：无法提供com.squareup.picasso.Picasso 没有@Inject构造函数或来自@ Provide-或 @ Produces-annotated方法。

在匕首2中实现这一目标的最佳方法是什么？

Answer 1

当组件A依赖于类型B时，你会说 B上的每个零arg getter都将在A的图形中可用。这意味着您不需要在NetComponent上单独调用inject，但您需要在NetComponent的定义中公开OkHttpClient。

这意味着NetComponent将如下所示：

@Singleton
@Component(modules={NetModule.class})
public interface NetComponent {
    /** Exposes OkHttpClient. Used by components depending on NetComponent. */
    OkHttpClient getOkHttpClient();
}

您的onCreateView可能如下所示：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,   
    Bundle savedInstanceState) {

  ((MyApp)getActivity().getApplication()).getImageComponent().inject(this);

}

在内部，Dagger在两个单独的步骤中生成DaggerNetComponent和DaggerImageComponent，但ImageComponent 调用新的getOkHttpClient method 。这也意味着DaggerImageComponent可以接受 NetComponent的任何实现，而不仅仅是Dagger生成的那个。

Dagger 2组件依赖不起作用

1 个答案: