如何在颤振中从谷歌地图获取位置的经纬度坐标？

Posted 2023-03-28

【中文标题】如何在颤振中从谷歌地图获取位置的经纬度坐标？

【英文标题】：How to get lat and long coordinates on location from google maps in flutter?

【发布时间】：2019-09-27 22:29:26

【问题描述】：

我使用的是 Flutter 1.3** 版本，它没有在 GoogleMap() 中定义 markers 语法

GoogleMap(
  onMapCreated: _onMapCreated,
  markers: markers,
)

所以我使用下面的代码来尝试从地图中获取经纬度

 void _onMapCreated(GoogleMapController controller)
    this._controller = controller;
    controller.onMarkerTapped.add(_onMarkerTapped);
          

  void _onMarkerTapped(Marker marker) 
         ...
           

Widget build(BuildContext context) 
   GoogleMap(
        onMapCreated: _onMapCreated,
        options: GoogleMapOptions(
          ...
        ));
      

我的问题是如何使用MarkerOptions 及以上方法将经纬度转换为字符串值？

【参考方案1】：

 LocationData currentLocation;


 getLocation() async 

  var location = new Location();

  location.onLocationChanged().listen((  currentLocation) 

    print(currentLocation.latitude);
    print(currentLocation.longitude);
    setState(() 

        latLng =  LatLng(currentLocation.latitude, currentLocation.longitude);
     );

    print("getLocation:$latLng");

      loading = false;
    );

  

从上面的代码中，您只需获得纬度和经度 并在

上使用这个 latLng 变量

  initialCameraPosition: CameraPosition(
      target: latLng,
      zoom: 17.4746,
    ),

GoogleMap 中的这个方法

【参考方案2】：

你可以使用 Marker 类的 onTap 方法来得到你想要的。

希望这会有所帮助！

  Map<MarkerId, Marker> markers = <MarkerId, Marker>;
  MarkerId selectedMarker;
  int _markerIdCounter = 1;

  void _add() 
    final int markerCount = markers.length;

    final String markerIdVal = 'marker_id_$_markerIdCounter';
    _markerIdCounter++;
    final MarkerId markerId = MarkerId(markerIdVal);

    final Marker marker = Marker(
      markerId: markerId,
      position: LatLng(
        center.latitude,
        center.longitude
      ),
      onTap: () 
        _onMarkerTapped(markerId);
      ,
    );

    setState(() 
      markers[markerId] = marker;
    );
  

  void _onMarkerTapped(MarkerId markerId) 
    final Marker tappedMarker = markers[markerId];
    if (tappedMarker != null) 
      setState(() 
        if (markers.containsKey(selectedMarker)) 
          print(selectedMarker.position.toString());
      
    
  

【参考方案3】：

此代码可能对您有所帮助。

    import 'dart:async';
    import 'package:flutter/material.dart';
    import 'package:google_maps_flutter/google_maps_flutter.dart';

    void main() => runApp(MyApp());

    class MyApp extends StatelessWidget 
      @override
      Widget build(BuildContext context) 
        return MaterialApp(
          title: 'Flutter Google Maps Demo',
          home: MapSample(),
        );
      
    

    class MapSample extends StatefulWidget 
      @override
      State<MapSample> createState() => MapSampleState();
    

    class MapSampleState extends State<MapSample> 
      Completer<GoogleMapController> _controller = Completer();

      static final CameraPosition _kGooglePlex = CameraPosition(
        target: LatLng(37.42796133580664, -122.085749655962),
        zoom: 14.4746,
      );

      static final CameraPosition _kLake = CameraPosition(
          bearing: 192.8334901395799,
          target: LatLng(37.43296265331129, -122.08832357078792),
          tilt: 59.440717697143555,
          zoom: 19.151926040649414);

      @override
      Widget build(BuildContext context) 
        return new Scaffold(
          body: GoogleMap(
            mapType: MapType.hybrid,
            initialCameraPosition: _kGooglePlex,
            onMapCreated: (GoogleMapController controller) 
              _controller.complete(controller);
            ,
          ),
          floatingActionButton: FloatingActionButton.extended(
            onPressed: _goToTheLake,
            label: Text('To the lake!'),
            icon: Icon(Icons.directions_boat),
          ),
        );
      

      Future<void> _goToTheLake() async 
        final GoogleMapController controller = await _controller.future;
        controller.animateCamera(CameraUpdate.newCameraPosition(_kLake));
      
    

【讨论】：

它不能回答我的问题，这个答案只显示标记不能选择位置，不能选择经纬度。