srt_app/lib/pages/map.dart

import 'dart:convert';

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

import 'package:flutter_map/flutter_map.dart';
import 'package:flutter_map/plugin_api.dart';
import 'package:latlong2/latlong.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
}

class MapScreen extends StatefulWidget {
  const MapScreen({Key? key}) : super(key: key);

  @override
  State<MapScreen> createState() => _MapScreenState();
}

class _MapScreenState extends State<MapScreen> {
  List _stations = [];
  List<Marker> _markers = [];

  @override
  void initState() {
    super.initState();

    _getStations();
  }

  Future<void> _getStations() async {
    final String stationFile =
        await rootBundle.loadString("assets/data/stations.json");
    final data = await json.decode(stationFile);

    List<Marker> markers = [];

    for (var i = 0; i < _stations.length; i++) {
      markers.add(
        Marker(
          height: 30,
          width: 30,
          point: LatLng(double.tryParse(_stations[i][4].toString()) ?? 0,
              double.tryParse(_stations[i][5].toString()) ?? 0),
          builder: (ctx) => const Icon(Icons.pin_drop),
        ),
      );
    }

    setState(() {
      _stations = data["records"];
      _markers = markers;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Home'),
        actions: <Widget>[
          IconButton(
            icon: const Icon(Icons.more_vert),
            onPressed: () {
              ScaffoldMessenger.of(context)
                  .showSnackBar(const SnackBar(content: Text('More')));
            },
          )
        ],
      ),
      floatingActionButton: FloatingActionButton(
          onPressed: () => {print("deez")}, child: const Icon(Icons.add)),
      body: FlutterMap(
        options:
            MapOptions(center: const LatLng(13.736717, 100.523186), zoom: 2.0),
        children: [
          TileLayer(
            urlTemplate: 'https://tile.openstreetmap.org/{z}/{x}/{y}.png',
            userAgentPackageName: 'net.winscloud,net',
          ),
          MarkerLayer(markers: _markers)
        ],
      ),
    );
  }
}