我正在尝试将我的 MainActivity 注入(inject) fragment 。我有一个在我的 MainActivity 中实现的接口(interface),它将监听来自 Fragment 的事件。所以我想注入(inject) MainActivity 并在其上调用事件监听器。
我已尝试执行以下操作,但未能成功。仅显示代码 fragment 。
界面
public interface RecipeItemListener {
void onRecipeItem();
}
实现接口(interface)的MainActivity
public class MainActivity extends AppCompatActivity implements RecipeItemListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(savedInstanceState == null) {
getSupportFragmentManager()
.beginTransaction()
.add(R.id.main_fragment_container, RecipeListView.newInstance(), RecipeListView.TAG)
.commit();
}
}
@Override
public void onRecipeItem() {
Timber.d("onRecipeItem");
}
}
我的提供 MainActivity 的模块
@Module
public class RecipeListModule {
private MainActivity mainActivity;
public RecipeListModule(MainActivity mainActivity) {
this.mainActivity = mainActivity;
}
@RecipeListScope
@Provides
public RecipeItemListener providesRecipeListMainActivity() {
return mainActivity;
}
}
我的主要组件
@Singleton
@Component(modules = {
AndroidModule.class,
NetworkModule.class})
public interface BusbyBakingComponent {
RecipeListComponent add(RecipeListModule recipeListModule);
}
我的子组件
@RecipeListScope
@Subcomponent(modules = {RecipeListModule.class})
public interface RecipeListComponent {
void inject(RecipeListView target);
}
我的应用类
public class BusbyBakingApplication extends Application {
private BusbyBakingComponent applicationComponent;
private RecipeListComponent recipeListComponent;
@Override
public void onCreate() {
super.onCreate();
applicationComponent = createApplicationComponent();
}
public BusbyBakingComponent createApplicationComponent() {
return DaggerBusbyBakingComponent.builder()
.networkModule(new NetworkModule())
.androidModule(new AndroidModule(BusbyBakingApplication.this))
.build();
}
public BusbyBakingComponent getApplicationComponent() {
return applicationComponent;
}
public RecipeListComponent createRecipeListComponent(MainActivity activity) {
recipeListComponent = applicationComponent.add(new RecipeListModule(activity));
return recipeListComponent;
}
public void releaseRecipeListComponent() {
recipeListComponent = null;
}
}
在我的 fragment 中,这就是我尝试注入(inject)的方式:
@Inject MainActivity mainActivity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((BusbyBakingApplication)getActivity().getApplication())
.createRecipeListComponent((MainActivity)getActivity())
.inject(RecipeListView.this);
}
我不断收到以下错误:
Error:(14, 8) error: [me.androidbox.busbybaking.di.RecipeListComponent.inject(me.androidbox.busbybaking.recipieslist.RecipeListView)] me.androidbox.busbybaking.recipieslist.MainActivity cannot be provided without an @Inject constructor or from an @Provides- or @Produces-annotated method.
me.androidbox.busbybaking.recipieslist.MainActivity is injected at
me.androidbox.busbybaking.recipieslist.RecipeListView.mainActivity
me.androidbox.busbybaking.recipieslist.RecipeListView is injected at
me.androidbox.busbybaking.di.RecipeListComponent.inject(target)
非常感谢您的任何建议。
最佳答案
如果你看一下你的模块
@RecipeListScope
@Provides
public RecipeItemListener providesRecipeListMainActivity() {
return mainActivity;
}
您提供接口(interface)(这很好)而不是 MainActivity
(实现)。
由于您请求 MainActivity
@Inject MainActivity mainActivity;
您收到此错误:
MainActivity cannot be provided [...]
因为您只提供RecipeItemListener
。
将您的代码从要求RecipeListView
中的MainActivity
更改为
@Inject RecipeItemListener recipeListener;
如果您的其余设置正确,它应该可以工作。
关于android - 如何使用 Dagger2 将 Activity 注入(inject)到 Fragment 中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44464841/