Flutter-谷歌地图标记导航到点击新屏幕

Question

(1) I'm creating a list of markers within a for loop using Json data from an api

for (var i in postCodesJson['records']) {
      Marker marker = Marker(
          markerId: MarkerId(i["fields"]["postal_code"].toString()),
          position: LatLng(i["fields"]["latitude"] as double,
              i["fields"]["longitude"] as double),
          icon: mapMarkImg!,
          onTap: () {
            Get.to(HomePage(pCode: i["fields"]["postal_code"].toString()));
          });

      list.add(marker);

(2) i want it so as to when i tap on the marker it opens the HomePage(String STRING) the home page takes in a string it uses to builds it content

(3) i tried using the get package but it is not working and tried using navigator but I don't have a context

(4) when using get and i tap on the markers nothing happens.

(5) here is my full code for the map page

import 'dart:async';
import 'dart:convert';
import 'package:area_app/main.dart';
import 'package:area_app/pages/home_page.dart';
import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:geocoding/geocoding.dart';
import 'package:http/http.dart' as http;
import 'package:get/get.dart';

class MapPage extends StatefulWidget {
  double longitude;
  double latitude;
  MapPage({Key? key, required this.longitude, required this.latitude})
      : super(key: key);
  @override
  _MapPageState createState() => _MapPageState(longitude, latitude);
}

double? cLat = latitude;
double? cLong = longitude;
String code = "";
Set<Marker> list = {};
BitmapDescriptor? mapMarkImg;

class _MapPageState extends State<MapPage> {
  double longitude;
  double latitude;
  _MapPageState(this.longitude, this.latitude);
  Completer<GoogleMapController> _controller = Completer();

  static final CameraPosition _kGooglePlex = CameraPosition(
    target: LatLng(cLat!, cLong!),
    zoom: 15.4746,
  );

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      //waits for stream to have data in it befor building the widget
      future: getCountry(longitude, latitude),
      builder: (context, snapshot) {
        return Scaffold(body: getBody(list));

        //returns the map
      },
    );
  }

  Widget getBody(Set<Marker> list) {
    return GoogleMap(
      //this gets the long and lat of the camera position and then returns a country code corisponding to that
      onCameraMove: (object) => {
        setState(() {
          cLat = object.target.latitude;
          cLong = object.target.longitude;
        })
      },
      markers: list,
      mapType: MapType.normal,
      buildingsEnabled: false,
      myLocationButtonEnabled: false,
      initialCameraPosition: _kGooglePlex,
      onMapCreated: (GoogleMapController controller) {
        _controller.complete(controller);
      },
    );
  }
}

//get country code
Future getCountry(double? long, double? lat) async {
  double lat1;

  double long1;
  lat1 = lat!;
  long1 = long!;
  mapMarkImg = await BitmapDescriptor.fromAssetImage(
      ImageConfiguration(), 'assets/images/marker.png');
  //code taken from geocoding pub dev page
  List<Placemark> placemarks = await placemarkFromCoordinates(lat1, long1);
  //get first entry in the list of placemarkers
  Placemark place = placemarks[0];
  if (code != place.isoCountryCode!) {
    code = place.isoCountryCode!;
    //get response
    var postCodesResponse = await http.get(Uri.parse(
        'https://data.opendatasoft.com/api/records/1.0/search/?dataset=geonames-postal-code%40public&q=${code}&rows=139&facet=country_code&facet=admin_name1&facet=admin_code1&facet=admin_name2'));

    final postCodesJson = jsonDecode(postCodesResponse.body.toString());
    //print(postCodesJson["records"][0]["datasetid"]);
    for (var i in postCodesJson['records']) {
      Marker marker = Marker(
          markerId: MarkerId(i["fields"]["postal_code"].toString()),
          position: LatLng(i["fields"]["latitude"] as double,
              i["fields"]["longitude"] as double),
          icon: mapMarkImg!,
          onTap: () {
            Get.to(HomePage(pCode: i["fields"]["postal_code"].toString()));
          });

      list.add(marker);
      print(list.length);
    }
  }
}

Answer 1

First of all check that is there any data in list (markers) variable and if there isn't any data then in Future getCountry(double? long, double? lat) function check that if (code.= place.isoCountryCode!) { this condition is true or false is has to be true if add data into list .