android - onCreate中使用getActivity时，如何让onCreate在onCreateView之前加载？

Question

我有一个使用 GooglePlayAPI 获取位置的代码。在那段代码中，我使用了 getAcvitity，因为这是一个 fragment ，我把它放在我的 OnCreate 中。因为我希望在 recyclerview 中显示这些值，所以我将那部分代码放在了 onCreateView 中。不幸的是，位置代码导致我的 onCreate 在我的 onCreateView 之后加载，因此我有一个没有值的 recyclerview。我试图将我的位置代码放在我的 onCreateView 中，但这不起作用。有谁知道我的问题的解决方案？这是我的代码。

public class TestFragment extends Fragment {
private double latitude;
private static double longitude;

private FusedLocationProviderClient mFusedLocationClient;


RecyclerView mRecyclerView;
PlanetRecyclerViewAdapter adapter;
private OnFragmentInteractionListener mListener;

public TestFragment() {
    // Required empty public constructor
}


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);

    requestPermission();

    mFusedLocationClient = LocationServices.getFusedLocationProviderClient(getActivity());

    if (ActivityCompat.checkSelfPermission(getActivity(), ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)  {
        Toast.makeText(getActivity(), "Please provide Location Permission to continue ", Toast.LENGTH_LONG).show();
        return;
    }
    mFusedLocationClient.getLastLocation().addOnSuccessListener(getActivity(), new OnSuccessListener<Location>() {
        @Override
        public void onSuccess(Location location) {

            if (location != null) {
                latitude = location.getLatitude();
                longitude = location.getLongitude();

                System.out.println("This is latitude:" + latitude);



            }

        }
    });


    if (getArguments() != null) {
        mParam1 = getArguments().getString(ARG_PARAM1);
        mParam2 = getArguments().getString(ARG_PARAM2);



    }


}


private void requestPermission(){
    ActivityCompat.requestPermissions(getActivity(),new String[]{ACCESS_FINE_LOCATION}, 1);
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_test, container, false);



    mRecyclerView = (RecyclerView)view.findViewById(R.id.planet_recycler_view);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    mRecyclerView.addItemDecoration(new DividerItemDecoration(mRecyclerView.getContext(),DividerItemDecoration.VERTICAL));

    adapter = new PlanetRecyclerViewAdapter(items, mRecyclerView.getContext());
    mRecyclerView.setAdapter(adapter);




    return view;
}




@Override
public void onAttach(Context context) {
    super.onAttach(context);

    if (context instanceof OnFragmentInteractionListener) {
        mListener = (OnFragmentInteractionListener) context;
    } else {
        throw new RuntimeException(context.toString()
                + " must implement OnFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);
}

Answer 1

getLastLocation() 是异步代码，因此它发生在 onCreateView 之后。尝试像这样将 getLastLocation() 放在 onCreateView 中:

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                     Bundle savedInstanceState) {

// Inflate the layout for this fragment 
View view = inflater.inflate(R.layout.fragment_test, container, false);



mRecyclerView = (RecyclerView)view.findViewById(R.id.planet_recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
mRecyclerView.addItemDecoration(new DividerItemDecoration(mRecyclerView.getContext(),DividerItemDecoration.VERTICAL));

mFusedLocationClient.getLastLocation().addOnSuccessListener(getActivity(), new OnSuccessListener<Location>() {
    @Override 
    public void onSuccess(Location location) { 

        if (location != null) { 
            latitude = location.getLatitude(); 
            longitude = location.getLongitude(); 

            System.out.println("This is latitude:" + latitude); 
            adapter = new PlanetRecyclerViewAdapter(items, mRecyclerView.getContext());
            mRecyclerView.setAdapter(adapter);


        } 

    } 
}); 




return view;
} 

只有当您收到位置时，您才会设置适配器并将其附加到 recyclerview。我没有在您的代码中找到您为适配器声明项目的位置。