MapView在Android mvvm数据绑定中不显示Google地图[已解决]

问题描述

我正在尝试使用具有数据绑定功能的mapView设置google地图，并在地图上设置一些标记。当我对“ latlngs”进行硬编码时，我的地图工作正常，但是当我尝试设置从服务器获取的“ latlngs”时，地图不会显示。显示了标记，数据和设置标​​记没有问题，只有地图不起作用。还有Google徽标，以防您怀疑我的API密钥是否有效。这是我的代码。

这是片段

<input type="time" class="form-control" id="uhrzeit_beginn" name="uhrzeit_beginn" required>

这是我的viewmodel：

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();
}

xml中的

地图就像这样

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()));
    }
}

和服务器响应

<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" />

我找到了解决方案

问题是在响应调用上再次设置了“位置” mutablelivedata，并且再次调用了getMapAsync，我需要在该方法内添加mapView.onResume。

[{
"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","RecordedAt": "2020-09-30T10:34:04"}]

解决方法

您需要在Fragment中而不是在ViewModel中加载地图。将此代码移动到片段的onViewCreated

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