从 activity 调用父片段中的子片段中的方法

Question

在我的 MainActivity class 中，我有 3 个选项卡的查看寻呼机 fragmentHome class、fragmentHot class 和 FragmentCategoryclass

这里是fragmentCategory class:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
  View view;
  view = inflater.inflate(R.layout.fragmentcategory, container, false);
  FragmentTransaction transaction = getFragmentManager().beginTransaction();
  transaction.replace(R.id.category_fragment, new TabCategoryFragment());
  transaction.commit();
  return view;
}

在 TabCategoryFragment class 中，我有网格类别新闻，当单击项目网格时，我调用了：

FragmentTransaction transaction = getFragmentManager().beginTransaction();
Bundle bundle = new Bundle();
bundle.putString("category", arrDataZone.get(position).getZone_name());
bundle.putString("zoneid", arrDataZone.get(position).getZone_id());
ListCategoryFragment myFrag = new ListCategoryFragment();
myFrag.setArguments(bundle);
transaction.replace(R.id.category_fragment, myFrag,"listFramgnet");
transaction.addToBackStack("grid_category");
transaction.commit();

现在我想从 MainActivity 调用 ListCategoryFragment 中的方法或从 FragmentCategory 调用 ListCategoryFragment 中的方法。

因为我尝试从 MainACtivity 调用 FragmentCategory 中的方法：

linearPlayer.setOnClickListener(new OnClickListener() {
  @Override
  public void onClick(View v) {
    int number=viewPager.getCurrentItem();
    Fragment fragment= adapter.getItem(number);

    if (number==0) {
      ((FragmentHome)fragment).playAudioSerVice();
    } else if(number==1) {
      ((FragmentHot)fragment).playAudioSerVice();
    } else if( number==2) {
      ((FragmentNew)fragment).playAudioSerVice();
    } else if( number==3) {
      ((FragmentCategory)fragment).playAudioSerVice();
    }
  }
});

它运行。请给我你的想法或代码来做到这一点。

Answer 1

可以使用Eventbus postSticky解决，可以看到api,eventbus

我写了一个demo来模拟你的case.Here就是代码。主要活动：

 public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main22);
        getSupportFragmentManager().beginTransaction().replace(R.id.contaner,new MainActivityFragment()).commit();
        EventBus.getDefault().register(this);
    }

    @Subscribe
    public void changeFragment(ChangeFragmentEvent event) {
        // get event from MainActivityFragment immediately--->EventBus.getDefault().post(new ChangeFragmentEvent());
        getSupportFragmentManager().beginTransaction().replace(R.id.contaner,PlusOneFragment.newInstance()).commit();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        EventBus.getDefault().unregister(this);
    }
}

MainActivityFragment:

    public class MainActivityFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_main22, container, false);
    }
    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        View button = view.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EventBus.getDefault().post(new ChangeFragmentEvent());//notify MainActivity change fragment
                EventBus.getDefault().postSticky(new MEvent());//send a msg to PlusOneFragment,when it shown 
            }
        });
    }
}

PlusOne片段：

    public class PlusOneFragment extends Fragment {

    public PlusOneFragment() {
    }

    public static PlusOneFragment newInstance() {
        PlusOneFragment fragment = new PlusOneFragment();
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EventBus.getDefault().register(this);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_plus_one, container, false);
        return view;
    }

    @Subscribe(sticky = true)
    public void getMEvent(MEvent event){
        // get event from MainActivityFragment when PlusOneFragment show --->EventBus.getDefault().postSticky(new MEvent());
        Toast.makeText(getActivity(),"Hello,there",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onDetach() {
        super.onDetach();
        EventBus.getDefault().unregister(this);
    }

}

从 activity 调用父片段中的子片段中的方法

Call method in child fragment in parent fragment from activity

android

fragment

android-fragments