آموزش کار با GPS و دریافت لوکیشن موقعیت کاربر در فلاتر

dependencies: 
flutter: sdk:
 flutter geolocator: ^5.1.3

<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs access to location when open.</string>

<key>NSLocationAlwaysUsageDescription</key>
<string>This app needs access to location when in the background.</string>

<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>This app needs access to location when open and in the background.</string>

NSLocationAlwaysUsageDescription 
NSLocationAlwaysAndWhenInUseUsageDescription

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

import 'package:flutter/material.dart';

import 'home_page.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: HomePage(),
    );
  }
}

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Location"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            FlatButton(
              child: Text("Get location"),
              onPressed: () {
                // Get location here
              },
            ),
          ],
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:geolocator/geolocator.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  Position _currentPosition;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Location"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            if (_currentPosition != null)
              Text(
                  "LAT: ${_currentPosition.latitude}, LNG: ${_currentPosition.longitude}"),
            FlatButton(
              child: Text("Get location"),
              onPressed: () {
                _getCurrentLocation();
              },
            ),
          ],
        ),
      ),
    );
  }

  _getCurrentLocation() {
    final Geolocator geolocator = Geolocator()..forceAndroidLocationManager;

    geolocator
        .getCurrentPosition(desiredAccuracy: LocationAccuracy.best)
        .then((Position position) {
      setState(() {
        _currentPosition = position;
      });
    }).catchError((e) {
      print(e);
    });
  }
}

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:geolocator/geolocator.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  final Geolocator geolocator = Geolocator()..forceAndroidLocationManager;

  Position _currentPosition;
  String _currentAddress;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Location"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            if (_currentPosition != null) Text(_currentAddress),
            FlatButton(
              child: Text("Get location"),
              onPressed: () {
                _getCurrentLocation();
              },
            ),
          ],
        ),
      ),
    );
  }

  _getCurrentLocation() {
    geolocator
        .getCurrentPosition(desiredAccuracy: LocationAccuracy.best)
        .then((Position position) {
      setState(() {
        _currentPosition = position;
      });

      _getAddressFromLatLng();
    }).catchError((e) {
      print(e);
    });
  }

  _getAddressFromLatLng() async {
    try {
      List<Placemark> p = await geolocator.placemarkFromCoordinates(
          _currentPosition.latitude, _currentPosition.longitude);

      Placemark place = p[0];

      setState(() {
        _currentAddress =
            "${place.locality}, ${place.postalCode}, ${place.country}";
      });
    } catch (e) {
      print(e);
    }
  }
}