使用谷歌地图颤动点击按钮时如何激活位置？

Question

我是使用 Flutter 的新手，我正在制作一个应用程序。因为我需要使用谷歌地图并仅在通过按钮激活时显示我的位置。

我正在使用以下示例：

https://pub.dartlang.org/packages/google_maps_flutter

这为您提供了一个将相机重定向到某个点的按钮，但是我如何才能将该按钮变为使用我的位置的触发器？

我做了这样的事情，但我收到一个错误：

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:location/location.dart' as LocationManager;

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

class Lugares extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Lugares',
      home: MapSample(),
      debugShowCheckedModeBanner: false,
    );
  }
}

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);
        },
        myLocationEnabled: true,
      ),
      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(CameraPosition(
        target: getUserLocation() == null ? LatLng(0, 0) : getUserLocation(), zoom: 15.0)));
  }

  Future<LatLng> getUserLocation() async {
    var currentLocation = <String, double>{};
    final location = LocationManager.Location();
    try {
      currentLocation = (await location.getLocation()) as Map<String, double>;
      final lat = currentLocation["latitude"];
      final lng = currentLocation["longitude"];
      final center = LatLng(lat, lng);
      return center;
    } on Exception {
      currentLocation = null;
      return null;
    }
  }

}

更新：

感谢@Vishal G. Gohel 分享了他的代码，我可以完成我想要的，这是代码：

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

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

class Lugares extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Lugares',
      home: MapSample(),
      debugShowCheckedModeBanner: false,
    );
  }
}

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,
  );

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: GoogleMap(
        mapType: MapType.hybrid,
        initialCameraPosition: _kGooglePlex,
        onMapCreated: (GoogleMapController controller) {
          _controller.complete(controller);
        },
        myLocationEnabled: true,
      ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: _currentLocation,
        label: Text('Ir a mi Ubicacion!'),
        icon: Icon(Icons.location_on),
      ),
    );
  }



void _currentLocation() async {
   final GoogleMapController controller = await _controller.future;
   LocationData currentLocation;
   var location = new Location();
   try {
     currentLocation = await location.getLocation();
     } on Exception {
       currentLocation = null;
       }

    controller.animateCamera(CameraUpdate.newCameraPosition(
      CameraPosition(
        bearing: 0,
        target: LatLng(currentLocation.latitude, currentLocation.longitude),
        zoom: 17.0,
      ),
    ));
  }

}

Answer 1

您可以查看我为获取当前位置而制作的以下方法。

void _currentLocation() async {
    Location _location = new Location();
    Map<String, double> location;

    try {
      location = await _location.getLocation();
    } on PlatformException catch (e) {
      print(e.message);
      location = null;
    }

    mapController.animateCamera(CameraUpdate.newCameraPosition(
      CameraPosition(
        bearing: 0,
        target: LatLng(location["latitude"], location["longitude"]),
        zoom: 17.0,
      ),
    ));

    mapController.addMarker(
      MarkerOptions(
        position: LatLng(location["latitude"], location["longitude"]),
      ),
    );
  }