匕首2注射无效

本文介绍了匕首2注射无效的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

提供Gson，Retrofit和OkHttpClient单例的模块

The module that proides singletons of Gson, Retrofit and OkHttpClient

@Module public class MyModule { @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; } }

允许将单例插入活动和片段的组件

The component that allows injecting the Singletons into activity and fragments

@Singleton @Component(modules={MyModule.class}) public interface MyComponent { void inject(Activity activity); void inject(Fragment fragment); void inject(Application application); }

构建组件的主应用程序类

The main application class that builds the component

public class MyApp extends Application{ private MyComponent component; @Inject Retrofit retrofit; @Override public void onCreate() { super.onCreate(); component= DaggerMyComponent.builder() .myModule(new MyModule()).build(); getComponent().inject(this); // inject retrofit here } public MyComponent getComponent() { return component; } }

这是我要注入改造的片段

This is the Fragment where I am trying to inject Retrofit.

public class MyFragment extends Fragment { @Inject Retrofit retrofit; @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { ((MyApp)getActivity().getApplication()).getComponent().inject(this); .... } }

在MyApp和MyFragment中，改装实例均为null。

In both MyApp and MyFragment the retrofit instance is null.

推荐答案

您可以在同一组件中注入Activity，Fragment和Application。需要为每个Activity，Fragment和Component创建单独的组件，例如：

You can inject Activity,Fragment and Application in Same Component.You need to create Separate component for each Activity ,Fragment and Component Like this:

Activiy

在所有活动中使用此组件：

Use this component in all your activity:

@Singleton @Component(modules={MyModule.class}) public interface MyActivityComponent { void inject(Activity activity); void inject(AnotherActivity activity); }

像这样注入活动：

component= DaggerMyActivityComponent.builder() .myModule(new MyModule()).build(); getComponent().inject(this)

片段

在所有片段中使用此组件：

Use this component in all your fragment:

@Singleton @Component(modules={MyModule.class}) public interface MyFragmentComponent { void inject(Fragment fragment); void inject(AnotherFragmen fragment); }

像这样插入片段：

component= DaggerMyFragmentComponent.builder() .myModule(new MyModule()).build(); getComponent().inject(this)

应用

在应用程序中使用此组件：

Use this component in your Application:

@Singleton @Component(modules={MyModule.class}) public interface MyAppComponent { void inject(Application application); }

像这样注入应用程序：

component= DaggerMyAppComponent.builder() .myModule(new MyModule()).build(); getComponent().inject(this)