Question

我正在尝试使用dagger 2在我的项目中实现Retrofit，它给了我以下错误：

Error:(22, 10) error: com.toranj.tyke.restApi.LotteryApiInterface cannot be provided without an @Provides- or @Produces-annotated method.
com.toranj.tyke.restApi.LotteryApiInterface is injected at
com.toranj.tyke.ui.MainActivity.LotteryApiInterface
com.toranj.tyke.ui.MainActivity is injected at
com.toranj.tyke.dagger.components.NetworkComponent.inject(activity)

所以这是我的 LotteryApiInterface ：

public interface LotteryApiInterface {
    @GET("/lottery/search")
    Call<List<Lottery>> getByCriteria(@Query("q") String query);

    @GET("lottery/details")
    Call<Lottery> getById(@Query("Id") String id);
}

这是 LotteryComponent ：

@PerActivity
@Component(dependencies = NetworkComponent.class, modules = LotteryModule.class)
public interface LotteryComponent {
    void inject(MainActivity activity);

}

然后我的 LotteryModule ：

@Module
public class LotteryModule {

    @Provides
    @PerActivity
    public LotteryApiInterface providesLotteryApiInterface(Retrofit retrofit) {
        return retrofit.create(LotteryApiInterface.class);
    }
}

当我清洁＆gt;重建项目，即使我的LotteryModule具有对象的@Provides注释，它也会给我错误。

可能我在这里遗漏了一些东西。任何帮助表示赞赏。

编辑：在我的Application类中创建了Retrofit，如下所示：

public class TykeApp extends Application {

    private NetworkComponent networkComponent;

    @Override
    public void onCreate() {
        super.onCreate();

        networkComponent = DaggerNetworkComponent.builder()
                .appModule(new AppModule(this))
                .networkModule(new     NetworkModule("http://192.168.0.3:8080"))
                .build();
    }

    public NetworkComponent getNetworkComponent() {
        return networkComponent;
    }
}

NetworkComponent ：

@Singleton
@Component(modules = { AppModule.class, NetworkModule.class })
public interface NetworkComponent {
    void inject(MainActivity activity);

    Retrofit retrofit();
    OkHttpClient okHttpClient();
    SharedPreferences sharedPreferences();
}

NetworkModule：

@Module
public class NetworkModule {

    String baseUrl;

    public NetworkModule(String baseUrl) {
        this.baseUrl = baseUrl;
    }

    @Provides
    SharedPreferences provideSharedPreferences(Application application) {
        return PreferenceManager.getDefaultSharedPreferences(application);
    }

    @Provides
    OkHttpClient provideOkhttpClient() {
        OkHttpClient.Builder client = new OkHttpClient.Builder();
        return client.build();
    }

    @Provides
    Retrofit provideRetrofit(OkHttpClient httpClient) {
        return new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(baseUrl)
                .client(httpClient)
                .build();
    }
}

这是MainActivity：

public class MainActivity extends BaseActivity {

    @Inject
    Retrofit retrofit;

    @Inject
    LotteryApiInterface LotteryApiInterface;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ((TykeApp)getApplication()).getNetworkComponent().inject(this);

        LotteryComponent lotteryComponent = DaggerLotteryComponent.builder()
                .lotteryModule(new LotteryModule())
                .build();
        lotteryComponent.inject(this);
    }
}

当我使用

时

@Inejct 
LotteryApiInterface LotteryApiInterface;

它会抛出给定的错误消息。

Answer 1

在Dagger2中使用字段注入时，您使用component.inject(this);的组件需要能够提供 每个依赖 您标有@Inject。

这意味着在您的情况下，您不应该

    ((TykeApp)getApplication()).getNetworkComponent().inject(this);

相反，你应该

    LotteryComponent lotteryComponent = DaggerLotteryComponent.builder()
            .networkComponent(((TykeApp)getApplication()).getNetworkComponent())
            .lotteryModule(new LotteryModule())
            .build();
    lotteryComponent.inject(this);

但值得注意的是，您的网络模块应该是

@Module
public class NetworkModule {

    String baseUrl;

    public NetworkModule(String baseUrl) {
        this.baseUrl = baseUrl;
    }

    @Provides
    SharedPreferences provideSharedPreferences(Application application) {
        return PreferenceManager.getDefaultSharedPreferences(application);
    }

    @Provides
    @Singleton
    OkHttpClient provideOkhttpClient() {
        OkHttpClient.Builder client = new OkHttpClient.Builder();
        return client.build();
    }

    @Provides
    @Singleton
    Retrofit provideRetrofit(OkHttpClient httpClient) {
        return new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(baseUrl)
                .client(httpClient)
                .build();
    }
}

你的NetworkComponent应该是

@Singleton
@Component(modules = { AppModule.class, NetworkModule.class })
public interface NetworkComponent {
    Retrofit retrofit();
    OkHttpClient okHttpClient();
    SharedPreferences sharedPreferences();
}

Android Dagger 2要求@Provides，而它就在那里

1 个答案: