How to Add Multiple Markers on Google Map in Flutter?

Last Updated : 20 Jan, 2023

Google Maps is one of the popular apps used nowadays for navigation or locating markers on Google Maps. We have seen markers on Google Maps for various locations. In this article, we are going to see how to implement multiple markers on Google Maps in Flutter.

Step By Step Implementation

Step 1: Create a New Project in Android Studio

To set up Flutter Development on Android Studio please refer to Android Studio Setup for Flutter Development, and then create a new project in Android Studio please refer to Creating a Simple Application in Flutter.

Step 2: Generating API Key for Using Google Maps

Check out the below article on How to generate an API key for using Google Maps. After developing that key we have to use it within our project to integrate Google Maps.

Now, follow the Steps to Implement Google Maps in the Flutter Application

Step 3: Adding Dependency to pubspec.yaml File

dependencies:
    flutter: 
    google_maps_flutter: ^2.1.8

Now click on pub.get to configure.

Step 4: Update build.gradle File

Navigate to android>app>build.gradle file and update code on below line.

Change Compile SDK Version

android {
    compileSdkVersion 31

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

Change Min SDK Version

defaultConfig {
    // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.example.google_maps"
    minSdkVersion 20
    targetSdkVersion 30
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
}

Step 5: Add API Key to Android Manifest File

Navigate to android > app > src > main > AndrodManifest.xml file and add the below code in the manifest tag. Make sure to add your Google Maps API key in the value.

<meta-data android:name="com.google.android.geo.API_KEY"
        android:value="Enter your API key here"/>

Step 6: Working with main.dart File

Navigate to lib > main.dart file and add the below code to it. Comments are added in the code to get to know in detail.

Dart

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'GFG',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      // First Screen of our App
      home: const HomePage(),
    );
  }
}

Step 7: Creating a new Dart File for Home Page

Navigate to lib > Right click on it > New > Dart File and name it as HomePage.dart. After creating that file add the below code to it. Comments are added in the code to get to know in detail.

Dart

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

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

  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {

  // on below line we are initializing our controller for google maps. 
  Completer<GoogleMapController> _controller = Completer();

  // on below line we are specifying our camera position
  static final CameraPosition _kGoogle = const CameraPosition(
      target: LatLng(37.42796133580664, -122.885749655962),
    zoom: 14.4746,
  );

  // on below line we have created list of markers
  List<Marker> _marker = [];
  final List<Marker> _list = const [
    // List of Markers Added on Google Map
    Marker(
        markerId: MarkerId('1'),
      position: LatLng(20.42796133580664, 80.885749655962),
      infoWindow: InfoWindow(
        title: 'My Position',
      )
    ),

    Marker(
        markerId: MarkerId('2'),
        position: LatLng(25.42796133580664, 80.885749655962),
        infoWindow: InfoWindow(
          title: 'Location 1',
        )
    ),

    Marker(
        markerId: MarkerId('3'),
        position: LatLng(20.42796133580664, 73.885749655962),
        infoWindow: InfoWindow(
          title: 'Location 2',
        )
    ),
  ];

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _marker.addAll(_list);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Color(0xFF0F9D58),
        title: Text("GFG"),
      ),
      body: Container(
        // on below line creating google maps. 
        child: GoogleMap(
          // on below line setting camera position 
            initialCameraPosition: _kGoogle,
          // on below line specifying map type. 
          mapType: MapType.normal,
          // on below line setting user location enabled.
          myLocationEnabled: true,
          // on below line setting compass enabled. 
          compassEnabled: true,
          // on below line specifying controller on map complete. 
          onMapCreated: (GoogleMapController controller){
              _controller.complete(controller);
          },
        ),
      )
    );
  }
}