android - MapView 在 Android mvvm 数据绑定(bind)中不显示谷歌地图 [已解决]

Question

我正在尝试使用带有数据绑定(bind)的 mapView 设置谷歌地图，并在 map 上设置一些标记。当我硬编码“latlngs”时，我的 map 工作正常，但是当我尝试设置从服务器获取的“latlngs”时， map 没有显示。显示标记，数据和设置标​​记没有问题，只有 map 不起作用。如果您想知道我的 API key 是否有效，还有 google Logo 。这是我的代码。
这是 fragment

private MapView google_map;

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

}

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

    FragmentMapBinding binding = DataBindingUtil.inflate(inflater, R.layout.fragment_map, container, false);
    MapFragmentViewModel viewModel = new ViewModelProvider(this, new MapFragmentViewModelFactory()).get(MapFragmentViewModel.class);

    binding.setLifecycleOwner(this);
    binding.setViewModel(viewModel);
    
    google_map = binding.googleMap;

    viewModel.getLocations();
    viewModel.locationsResponse().observe(getViewLifecycleOwner(), apiResponseObject -> {
        switch (apiResponseObject.status) {
            case SUCCESS:
                ViewUtils.hideProgressDialog();
                break;
            case LOADING:
                ViewUtils.showProgressDialog(requireContext());
                break;
            case ERROR:
                ViewUtils.hideProgressDialog();
                ViewUtils.showToastMessage(requireContext(), apiResponseObject.error);
        }
    });

    setTypeFace(binding.getRoot(), requireContext());
    languageSetup(requireContext());
    return binding.getRoot();
}

@Override
public void onResume() {
    super.onResume();
    google_map.onResume();
}

@Override
public void onPause() {
    super.onPause();
    google_map.onPause();
}

@Override
public void onDestroy() {
    super.onDestroy();
    google_map.onDestroy();
}

@Override
public void onLowMemory() {
    super.onLowMemory();
    google_map.onLowMemory();
}

@Override
public void onStop() {
    super.onStop();
    google_map.onStop();
}

这是我的 View 模型:

private MutableLiveData<ApiResponseObject> responseLiveData = new MutableLiveData<>();
private CompositeDisposable disposables;
private ApiCallsRepository apiCallsRepository;

public MapFragmentViewModel() {
    apiCallsRepository = new ApiCallsRepository();
    disposables = new CompositeDisposable();

}

void getLocations() {

    disposables.add(apiCallsRepository.getLocations(SharedPrefUtils.getUserId())
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .doOnSubscribe(disposable -> responseLiveData.setValue(ApiResponseObject.loading()))
            .subscribe(this::setLocations, this::handleError));

}

LiveData<ApiResponseObject> locationsResponse() {
    return responseLiveData;
}

public MutableLiveData<List<LatLng>> locations = new MutableLiveData<>();

@BindingAdapter("initMap")
public static void initMap(final MapView mapView, final List<LatLng> locations) {

    if (mapView != null) {
        mapView.onCreate(new Bundle());
        mapView.getMapAsync(googleMap -> {
            if (locations != null) {
                for (LatLng latLng : locations)
                    googleMap.addMarker(new MarkerOptions().position(latLng));
            }
        });
    }
}

public void setLocations(List<LocationsResponse> mLocationsResponses) {

    List<LatLng> latLngs = new ArrayList<>();

    for (LocationsResponse locationsResponse : mLocationsResponses)
            latLngs.add(new LatLng(Double.parseDouble(locationsResponse.getLongitude()), 
                    Double.parseDouble(locationsResponse.getLatitude())));

    locations.setValue(latLngs);
    responseLiveData.setValue(ApiResponseObject.success(null));
}

private void handleError(Throwable throwable) {
    if (throwable instanceof HttpException) {
        HttpException httpException = (HttpException) throwable;
        Response<?> response = httpException.response();
        responseLiveData.setValue(ApiResponseObject.error(getErrorMessage(response)));
    } else if (throwable instanceof IOException) {
        responseLiveData.setValue(ApiResponseObject.error(UNEXPECTED_ERROR));
    } else {
        responseLiveData.setValue(ApiResponseObject.error(throwable.getMessage()));
    }
}

xml中的 map 是这样的

<com.google.android.gms.maps.MapView
        android:id="@+id/google_map"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:initMap="@{viewModel.locations}"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tvTextWarning" />

和服务器响应

[{
"Latitude": "19.8164793",
"Longitude": "45.2628729",
"Elevation": "128.6999969482422",
"RecordedAt": "2020-09-30T09:32:56"},{
"Latitude": "19.8164799",
"Longitude": "45.2628755",
"Elevation": "129.60000610351562",
"RecordedAt": "2020-09-30T10:35:42"},{
"Latitude": "19.8164801",
"Longitude": "45.262874",
"Elevation": "129.60000610351562",
"RecordedAt": "2020-09-30T10:34:04"}]

我找到了解决方案
问题是在响应调用中再次设置“位置” mutableLiveData，并且再次调用 getMapAsync，我需要在该方法中添加 mapView.onResume。

@BindingAdapter("initMap")
public static void initMap(final MapView mapView, final List<LatLng> locations) {

    if (mapView != null) {
        mapView.onCreate(new Bundle());
        mapView.getMapAsync(googleMap -> {
            if (locations != null) {
                mapView.onResume();
                for (LatLng latLng : locations)
                    googleMap.addMarker(new MarkerOptions().position(latLng));
            }
        });
    }
}

Answer 1

您需要在 Fragment 中加载 map ，而不是在 ViewModel 中。将此代码移动到 fragment 的 onViewCreated

mapView.getMapAsync(googleMap -> {
        if (locations != null) {
            for (LatLng latLng : locations)
                googleMap.addMarker(new MarkerOptions().position(latLng));
        }
    });