“Fragment”中可以用什么函数代替“this”？

Question

我正在 Google map place api 中实现自动完成建议代码。 我们使用OnMapReadyCallback 作为工具。

MapView.getMapAsync(this) 函数最初用于onCreateView。但现在我将在setupAutoCompleteFragment 中使用它。但是，在MapView.getMapAsync(this) 中，由于this，它没有被编译。有什么用？

public class googlemaptab extends Fragment implements OnMapReadyCallback {
    MapView mapview;
    Button kakaobutton;
    public static googlemaptab newInstance(){
        return new googlemaptab();
    }
    public googlemaptab() {
        // Required empty public constructor
    }

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

        mapview = (MapView)view.findViewById(R.id.google_map_view);
        setupAutoCompleteFragment();
        return view;
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        kakaobutton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //클릭하면 카카오maptab으로 이동하겠다.
                ((MainActivity)getActivity()).replaceFragment(kakaomaptab.newInstance());
            }
        });
    }

    @Override
    public void onStart() {
        super.onStart();
        mapview.onStart();
    }

    @Override
    public void onResume() {
        super.onResume();
        mapview.onResume();
    }
    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if(mapview != null)
        {
            mapview.onCreate(savedInstanceState);
        }

    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        LatLng SEOUL = new LatLng(37.56, 126.97);
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(SEOUL);
        markerOptions.title("서울");
        markerOptions.snippet("수도");
        googleMap.addMarker(markerOptions);
        googleMap.moveCamera(CameraUpdateFactory.newLatLng(SEOUL));
        googleMap.animateCamera(CameraUpdateFactory.zoomTo(13));
    }

    private void setupAutoCompleteFragment() {

        PlaceAutocompleteFragment autocompleteFragment = (PlaceAutocompleteFragment)getActivity().
                getFragmentManager().findFragmentById(R.id.place_autocomplete_fragment);
        autocompleteFragment.setOnPlaceSelectedListener(new PlaceSelectionListener() {
            @Override
            public void onPlaceSelected(Place place) {
                mapview.getMapAsync(this);
            }

            @Override
            public void onError(Status status) {
                Log.e("Error", status.getStatusMessage());
            }
        });
    }
}

Answer 1

这样可以做得更好

private void setupAutoCompleteFragment(OnMapReadyCallback instance) {

        PlaceAutocompleteFragment autocompleteFragment = (PlaceAutocompleteFragment)getActivity().
                getFragmentManager().findFragmentById(R.id.place_autocomplete_fragment);
        autocompleteFragment.setOnPlaceSelectedListener(new PlaceSelectionListener() {
            @Override
            public void onPlaceSelected(Place place) {
                mapview.getMapAsync(instance);
            }

            @Override
            public void onError(Status status) {
                Log.e("Error", status.getStatusMessage());
            }
        });
    }

别忘了用新的函数签名更新您的onCreateView，如下所示：

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

        mapview = (MapView)view.findViewById(R.id.google_map_view);
        setupAutoCompleteFragment(this);
        return view;
    }

Answer 2

在这种情况下，您可以使用Classname.this。

例如：如果你的片段名称是HomeFragment 那么，

HomeFragment.this

如果这仍然不起作用，那么您可以覆盖 onViewCreated() 函数并在 onViewCreated() 内调用 mapView.getMapAsync(this)

如果需要，请查看link

Answer 3

您是否尝试过 mapview.getMapAsync(getActivity());而不是 mapview.getMapAsync(this);