Question

我不知道为什么mainRankPresenter中由dagger2注入的MainRankPresenter.java的loginResponseHandler为null。我只想注入野外进行野外注射。我应该采取其他方式而不是现场注射吗？拜托，让我知道如何解决它。

BBBApplication.java

public class BBBApplication extends MultiDexApplication
{
    ...
    @Override
    public void onCreate() {
        super.onCreate();

        initAppComponent();
    }

    private void initAppComponent() {
        this.appComponent = DaggerAppComponent.builder()
            .appModule(new AppModule(this))
            .build();
    }

    public static BBBApplication get(Context ctx) {
        return (BBBApplication) ctx.getApplicationContext();
    }
    public AppComponent getAppComponent() {
        return this.appComponent;
    }
    ...
}

AppModule.java

@Module
public class AppModule {
    private BBBApplication application;

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

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

    @Provides
    @Singleton
    public Resources provideResources() {
        return this.application.getResources();
    }

    @Provides`enter code here`
    @Singleton
    public SharedPreferences provideSharedPreferences() {
        return PreferenceManager.getDefaultSharedPreferences(this.application);
    }
}

AppComponent.java

@Singleton
@Component(modules = {AppModule.class, ServiceModule.class})
public interface AppComponent {
    RankFragmentComponent plus(RankFragmentModule module);

    Application application();
    Resources resources();
}

RankFragmentModule.java

@Module
public class RankFragmentModule {

    private RankFragment rankFragment;

    public RankFragmentModule(RankFragment rankFragment) {
        this.rankFragment = rankFragment;
    }

    @Provides
    @ActivityScope
    public LoginResponseHandler provideLoginResponseHandler() {
        return new LoginResponseHandler(this.rankFragment);
    }

    @Provides
    @ActivityScope
//    @Named("rankFragment")
    public RankFragment provideRankFragment() {
        return this.rankFragment;
    }

    @Provides
    @ActivityScope
    public MainRankPresenter provideMainRankPresenter(RankFragment rankFragment) {
        return new MainRankPresenter(new MainRankViewOps(rankFragment));
    }

}

RankFragmentComponent.java

@ActivityScope
@Subcomponent(modules = {RankFragmentModule.class})
public interface RankFragmentComponent {
    void inject(RankFragment rankFragment);
}

RankFragment.java

public class RankFragment extends Fragment {

    @Inject
    MainRankPresenter presenter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        BBBApplication.get(getContext())
                .getAppComponent()
                .plus(new RankFragmentModule(this))
                .inject(this);
        presenter.test();
    }

MainRankPresenter.java

public class MainRankPresenter implements Presenter {

    private MainRankViewOps viewOps;

    @Inject
    LoginResponseHandler loginResponseHandler;

    @Inject
    public MainRankPresenter(MainRankViewOps viewOps) {
        this.viewOps = viewOps;
    }

    @Override
    public void test() {
        Log.d(Constants.TAG_DEBUG, "=== presenter test" + this.toString());
        Log.d(Constants.TAG_DEBUG, "=== " + loginResponseHandler.toString());
        this.viewOps.initViewOps();
    }
}

MainRankViewOps.java

public class MainRankViewOps implements ViewOps {

    RankFragment fragment;

    @Inject
    public MainRankViewOps(RankFragment fragment) {
        this.fragment = fragment;
    }

    @Override
    public void initViewOps() {
        Log.d(Constants.TAG_DEBUG, "=== view ops" + this.toString());
        Log.d(Constants.TAG_DEBUG, "=== " + fragment.toString());
    }
}

Answer 1

Dagger 2的注入不是递归的。因此，当您在inject(this)中调用RankFragment时，只会注入该片段的@Inject个注释字段。 Dagger 2不会在注入的对象中搜索@Inject注释。

通常，您应该尝试将依赖注入框架的使用限制为＆＃34;顶级＆＃34;组件（活动，片段，服务等），由Android框架为您实例化。在您自己实例化的对象中（如MainRankPresenter），您应该使用其他不涉及外部框架的DI技术（例如，依赖注入构造函数）。

Answer 2

因为你@Provides MainRankPresenter，Dagger不会注射它：你要对此承担责任。您可以将您的提供方法传递给MembersInjector，如果对象在返回之前可以注入字段，但它可能更好地重构您移除的模块，提供方法并让Dagger处理注射（你已经拥有了所有@Inject）

我不知道为什么dagger2注入的对象在演示者

2 个答案: