Question

我对dagger2全新，希望能帮助我:)。

我正在实施一个小型演示，但我承认以下错误：错误：（20,10）错误：如果没有@Inject构建器或@或@ Produces提供 - 注释方法，则无法提供android.net.ConnectivityManager。 com.edwin.dagger1.MainActivity.connectivityManager [注入的字段类型：android.net.ConnectivityManager connectivityManager]

＆＃13;

public class Dagger2Application extends Application {

    private SystemComponent systemComponent;

    @Override
    public void onCreate() {
        super.onCreate();
        systemComponent = DaggerSystemComponent.builder()
                .systemModule(new SystemModule(this))
                .build();
    }

    public SystemComponent getSystemComponent() {
        return systemComponent;
    }
}

＆＃13;

@Module
public class SystemModule {
    private final Application application;

    public SystemModule(Application application) {
        this.application = application;
    }

    @Provides
    @Singleton
    public Context provideContext(){
        return application;

＆＃13;

@Singleton
@Component(modules = SystemModule.class)
public interface SystemComponent {
    void inject(MainActivity activity);
}

＆＃13;

public class MainActivity extends AppCompatActivity {

    @Inject
    ConnectivityManager connectivityManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Dagger2Application dagger2Application=(Dagger2Application)getApplication();
        dagger2Application.getSystemComponent().inject(this);


        boolean activeNetworkMetered = connectivityManager.isActiveNetworkMetered();
        Log.d("Network is metered? " , activeNetworkMetered+"");
    }
}

＆＃13;

Answer 1

问题在于注入ConnectivityManager类。我修改了一些代码。请看看，希望这会帮助你

public interface IConnectivityManager {
    boolean getActiveNetworkMetered();
}


public class IConnectivityManagerImpl implements IConnectivityManager {

    private Context context;

    public IConnectivityManagerImpl(Context context) {
        this.context = context;
    }

    @Override
    public boolean getActiveNetworkMetered() {
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        return connectivityManager.isActiveNetworkMetered();
    }
}

MainActivity.class

 @Inject
    IConnectivityManager connectivityManager;
 boolean activeNetworkMetered = connectivityManagers.getActiveNetworkMetered();
        Log.d("Network is metered? " , activeNetworkMetered+"");

SystemModule.class

   @Provides
    @Singleton
    public IConnectivityManager provideConnectivity(Context context){
        return new IConnectivityManagerImpl(context);
    }

Dagger 2错误：如果没有@inject构造函数或@ provide-annotated方法

1 个答案: