Android Studio 3.0 金丝雀版 8
我试图将我的 MainActivity 注入到我的适配器中。然而,我的解决方案可以正常工作,但我认为这是一种代码异味并不是正确的做法。
我的适配器片段看起来像这样,但我不喜欢的是我必须将 Activity
强制转换为 MainActivity
:
public class RecipeAdapter extends RecyclerView.Adapter<RecipeListViewHolder> {
private List<Recipe> recipeList = Collections.emptyList();
private Map<Integer, RecipeListViewHolderFactory> viewHolderFactories;
private MainActivity mainActivity;
public RecipeAdapter(Activity activity, Map<Integer, RecipeListViewHolderFactory> viewHolderFactories) {
this.recipeList = new ArrayList<>();
this.viewHolderFactories = viewHolderFactories;
this.mainActivity = (MainActivity)activity;
}
@Override
public RecipeListViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
/* Inject the viewholder */
final RecipeListViewHolder recipeListViewHolder = viewHolderFactories.get(Constants.RECIPE_LIST).createViewHolder(viewGroup);
recipeListViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/* Using the MainActivity to call a callback listener */
mainActivity.onRecipeItemClick(getRecipe(recipeListViewHolder.getAdapterPosition()));
}
});
return recipeListViewHolder;
}
}
在我的模块中,我在构造函数中传递了Activity,并将其传递给了Adapter。
@Module
public class RecipeListModule {
private Activity activity;
public RecipeListModule() {}
public RecipeListModule(Activity activity) {
this.activity = activity;
}
@RecipeListScope
@Provides
RecipeAdapter providesRecipeAdapter(Map<Integer, RecipeListViewHolderFactory> viewHolderFactories) {
return new RecipeAdapter(activity, viewHolderFactories);
}
}
在我的应用程序类中,我创建了组件,并且使用了一个子组件作为适配器。在这里,我必须传递Activity,但我不确定这是否是一个好主意。
@Override
public void onCreate() {
super.onCreate();
applicationComponent = createApplicationComponent();
recipeListComponent = createRecipeListComponent();
}
public BusbyBakingComponent createApplicationComponent() {
return DaggerBusbyBakingComponent.builder()
.networkModule(new NetworkModule())
.androidModule(new AndroidModule(BusbyBakingApplication.this))
.exoPlayerModule(new ExoPlayerModule())
.build();
}
public RecipeListComponent createRecipeListComponent(Activity activity) {
return recipeListComponent = applicationComponent.add(new RecipeListModule(activity));
}
我是这样注入我的Fragment的:
@Inject RecipeAdapter recipeAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((BusbyBakingApplication)getActivity().getApplication())
.createRecipeListComponent(getActivity())
.inject(this);
}
尽管上述设计是可行的,但我认为它存在代码气味问题,因为我必须将 Activity 强制转换为 MainActivity。之所以使用 Activity,是因为我想使这个模块更加通用。不知道是否有更好的方法?
=============== 使用接口进行更新
接口
public interface RecipeItemClickListener {
void onRecipeItemClick(Recipe recipe);
}
实现
public class RecipeItemClickListenerImp implements RecipeItemClickListener {
@Override
public void onRecipeItemClick(Recipe recipe, Context context) {
final Intent intent = Henson.with(context)
.gotoRecipeDetailActivity()
.recipe(recipe)
.build();
context.startActivity(intent);
}
}
在我的模块中,我有以下提供者。
@Module
public class RecipeListModule {
@RecipeListScope
@Provides
RecipeItemClickListener providesRecipeItemClickListenerImp() {
return new RecipeItemClickListenerImp();
}
@RecipeListScope
@Provides
RecipeAdapter providesRecipeAdapter(RecipeItemClickListener recipeItemClickListener, Map<Integer, RecipeListViewHolderFactory> viewHolderFactories) {
return new RecipeAdapter(recipeItemClickListener, viewHolderFactories);
}
}
然后我通过构造函数注入在RecipeAdapter中使用它。
public class RecipeAdapter extends RecyclerView.Adapter<RecipeListViewHolder> {
private List<Recipe> recipeList = Collections.emptyList();
private Map<Integer, RecipeListViewHolderFactory> viewHolderFactories;
private RecipeItemClickListener recipeItemClickListener;
@Inject /* IS THIS NESSESSARY - AS IT WORKS WITH AND WITHOUT THE @Inject annotation */
public RecipeAdapter(RecipeItemClickListener recipeItemClickListener, Map<Integer, RecipeListViewHolderFactory> viewHolderFactories) {
this.recipeList = new ArrayList<>();
this.viewHolderFactories = viewHolderFactories;
this.recipeItemClickListener = recipeItemClickListener;
}
@Override
public RecipeListViewHolder onCreateViewHolder(final ViewGroup viewGroup, int i) {
/* Inject the viewholder */
final RecipeListViewHolder recipeListViewHolder = viewHolderFactories.get(Constants.RECIPE_LIST).createViewHolder(viewGroup);
recipeListViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
recipeItemClickListener.onRecipeItemClick(getRecipe(recipeListViewHolder.getAdapterPosition()), viewGroup.getContext());
}
});
return recipeListViewHolder;
}
}
我有一个问题,RecipeAdapter中的构造函数是否需要使用@Inject注解?因为它可以在有或没有@Inject的情况下正常工作。