如何访问react-native-map中的coords？

Question

我正在尝试通过使用react - native -map中的'coords‘属性在我的react原生应用程序中使用用户的当前位置。

问题是，当我尝试console.log currentLocation.coords时，我得到了错误：

TypeError: null is not an object (evaluating 'currentLocation.coords')

但是当我console.log currentLocation的时候，我可以看到响应中的和弦支点。

Object {
  "coords": Object {
    "accuracy": 5,
    "altitude": 5,
    "altitudeAccuracy": 5,
    "heading": 0,
    "latitude": 13.184791,
    "longtitude": 55.735991,
    "speed": 0,
  },
  "timestamp": 1000000,
}

const locationReducer = (state, action) => {
    switch (action.type) {
        case 'add_current_location':
            return { ...state, currentLocation: action.payload }
        default:
            return state;
    }
};

const startRecording = dispatch => () => {};
const stopRecording = dispatch => () => {};
const addLocation = dispatch => (location) => {
    dispatch({ type: 'add_current_location', payload: location })
};

export const { Context, Provider } = createDataContext(
    locationReducer,
   { startRecording, stopRecording, addLocation },
   { recording: false, locations: [], currentLocation: null }
);

const Map = () => {
    const { state: { currentLocation } } = useContext(LocationContext);

    console.log(currentLocation.coords);

    if (!currentLocation) {
        return <ActivityIndicator size="large" style={{ marginTop: 200 }} />;
    };

    return (
        <MapView
            style={styles.map}
            initialRegion={{
                ...currentLocation.coords,
                latitudeDelta: 0.01,
                longitudeDelta: 0.01
            }}
        >
        </MapView>
    );
};

const TrackCreateScreen = () => {
    const { addLocation } = useContext(LocationContext);
    const [err, setErr] = useState(null);

    const startWatching = async () => {
        try {
            await requestPermissionsAsync();
            await watchPositionAsync({
                accuracy: Accuracy.BestForNavigation,
                timeInterval: 1000,
                distanceInterval: 10
            }, (location) => {
                addLocation(location);
            });
        } catch (e) {
            setErr(e);
        }
    };

useEffect(() => {
    startWatching();
}, []);

我怎样才能访问coords？(我需要使用经度和纬度)

Answer 1

我使用了'react-native- location‘来获取用户的当前位置。在subscribeToLocationUpdates中，我获取纬度和经度，如下所示。

 let requestBody = await getPlaceNameFromLocation(locations[0].latitude, locations[0].longitude)

如您所见，我正在获取位置数组，这在您的情况下可能会出现问题。请查收。As数组也是object。