BottomSheetFragment + Frag with RecyclerView

Question

我正在使用三个类 - MainActivity，Frag1，BottomSheetFrag。 我使用一个简单的接口，通过MainAc将一个对象从BottomSheet发送到Frag1。哪个功能完美。但是当recyclerView设置适配器时，我得到了NullPointerException。

BottomSheet：

private EditText et_name;
private EditText et_contact;
private Button btn_ok;
ICommunic comm;

private BottomSheetBehavior.BottomSheetCallback
            mBottomSheetBehaviorCallback = new BottomSheetBehavior.BottomSheetCallback() {
    @Override
    public void onStateChanged(@NonNull View bottomSheet, int newState) {
        if (newState == BottomSheetBehavior.STATE_HIDDEN)
            dismiss();
    }

    @Override
    public void onSlide(@NonNull View bottomSheet, float slideOffset) {

    }
};
@Override
public void setupDialog(Dialog dialog, int style) {
    super.setupDialog(dialog, style);
    View v = View.inflate(getContext(), R.layout.fragment_BS, null);

    et_name = v.findViewById(R.id.et_nameV);
    et_contact = v.findViewById(R.id.et_contactV);
    btn_ok = v.findViewById(R.id.btn_save);

    btn_ok.setOnClickListener((View view) -> {
        Person p = new Person(et_name.getText().toString(), et_contact.getText().toString())

        comm.AddPerson(p);

});...

MainActivity实现接口

...
@Override
public void AddPerson(Person p) {
    Frag1.getPerson(p);
}

Frag1

private RecyclerView recyclerView;
private RecyclerView.Adapter adapter;
private ArrayList<Person> listPerson;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.frag1, container, false);

    recyclerView = view.findViewById(R.id.rv_person);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    return view;
}

public void getPerson(Person p) {
    listPerson.add(p);
    adapter = new AdapterRecV(getActivity(), listAluno);
    recyclerView.setAdapter(adapter);
}

Answer 1

通过定义List和适配器为静态，我能够达到预期的效果。