Question

我在活动中制作了一个android底部栏，并认为我会使用dagger2为其设置侦听器。我如何对如何在监听器类中获取 getSupportFragmentManager（）感到困惑。这就是我正在尝试的

public class MainActivity extends AppCompatActivity {

@BindView(R.id.bottomNavigationView)
BottomNavigationView bottomNavigationView;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);
    BottomBarComponent bottomBarComponent = DaggerBottomBarComponent.builder()
            .bottomBarModule(new BottomBarModule(getSupportFragmentManager()))
            .build();

}
}

组成部分是

@Singleton
@Component(modules = {BottomBarModule.class})
public interface BottomBarComponent {
 void inject(BottomNavigationListener listener);
}

模块是

@Module
public class BottomBarModule {
private FragmentManager manager;

public BottomBarModule(FragmentManager context) {
    this.manager = context;
}

@Singleton
@Provides
public FragmentManager provideSupportManager(){
    return manager;
}
}

并且需要在此处获取fragmentsupportManager

public class BottomNavigationListener implements BottomNavigationView.OnNavigationItemSelectedListener{


@Inject
FragmentManager manager;

public void BottomNavigationListener() {

   //somehow need to get fragmentSupportManager here
}

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {

    return true;
}
}

我该怎么做？

Answer 1

您需要与BottomBarComponent共享BottomNavigationListener的实例，并在其上调用inject()方法。

BottomNavigationListener.class

...
public void BottomNavigationListener(BottomBarComponent injector) {
   //somehow need to get fragmentSupportManager here
   injector.inject(this); // now manager field must be filled
}
...

MainActivity.class

...
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);
    BottomBarComponent bottomBarComponent = DaggerBottomBarComponent.builder()
            .bottomBarModule(new BottomBarModule(getSupportFragmentManager()))
            .build();
    // pass BottomBarComponent to BottomNavigationListener for injecting FragmentManager
    BottomNavigationListener listener = new BottomNavigationListener(bottomBarComponent);
}
...

但是您要尝试做的事情很奇怪。等同于无需使用Dagger就将FragmentManager直接传递到BottomNavigationListener。

匕首2注入物体

1 个答案: