Android 当启动其他片段时，应用程序停止

我有两个片段，当在片段1中单击布局时，我想开始片段2

片段1：

public class NewFlightTab extends Fragment {

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

    @Override
    public void onActivityCreated( Bundle savedInstanceState ){
        super.onActivityCreated(savedInstanceState);
        final RelativeLayout departureCityLayout = ( RelativeLayout )   getActivity().findViewById( R.id.depature_city_layout);
    departureCityLayout.setOnClickListener( new View.OnClickListener() {
        @Override
        public void onClick(View v) {
             getActivity().getSupportFragmentManager().beginTransaction().add( R.id.citiesAndAirport, new CitiesAndAirportFragment()).commit();
            }
        });

    }
}

片段2：

public class CitiesAndAirportFragment extends Fragment {
    private RecyclerView mRecyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager mLayoutManager;
    private ArrayList<String> citiesAndAirports;


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

    @Override
    public void onActivityCreated( Bundle savedInstanceState ){
        super.onActivityCreated(savedInstanceState);
        citiesAndAirports.add("Bangalore");
        mRecyclerView = (RecyclerView)   getActivity().findViewById(R.id.citiesAndAirport);
        mRecyclerView.setHasFixedSize(true);
        mLayoutManager = new LinearLayoutManager(getActivity());
        mRecyclerView.setLayoutManager( mLayoutManager );
        mAdapter = new CitiesAndAirportAdapter(citiesAndAirports);
        mRecyclerView.setAdapter( mAdapter );


    }
}

删除：

        mRecyclerView = (RecyclerView)   getActivity().findViewById(R.id.citiesAndAirport);

再次回顾：

 @Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v =inflater.inflate(R.layout.cities_airport_list,container,false);
    mRecyclerView = v.findViewById(R.id.citiesAndAirport);
    return v;
}

---

此外，在这里输入的代码中，您从未初始化CitiesAndAirport

黄金法则：如果你的应用程序崩溃，那么总是发布日志。实际上，它在调用beginTransaction（）的add（）时崩溃。尝试在你的事务中用android.R.id.content替换R.id.citiesAndAirport。你提供的id应该是你打开第二个片段的容器的id/。如果要将其放在活动布局中，请提供该根布局的id。

        mRecyclerView = (RecyclerView)   getActivity().findViewById(R.id.citiesAndAirport);

 @Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v =inflater.inflate(R.layout.cities_airport_list,container,false);
    mRecyclerView = v.findViewById(R.id.citiesAndAirport);
    return v;
}