How to create a service in Flutter to make an app to run always in background?

Question

I would like to make my Flutter application to run always in background. With android, we have to create a Service that runs always in background. I don't find something about Services in the Flutter documentation.

Is it possible to do this kind of things with Flutter?

Answer 1

There isn't a way to do this directly from flutter right now although that may change at some point - see this bug/feature request. You do have a couple of options though.

The first is to use MethodChannels and simply write the android code you want to create a background service (or if you want it to always be a background service you can probably do that without needing communication from the flutter side).

The second is some combination of these two plugins - android_alarm_manager and android_intent. But that won't help for all use-cases.

EDIT Feb 2021:

Flutter now supports running background processes. See this page for details.

Answer 2

• create new Flutter project.
  • create BroadcastReceiver class beside MainActivity in android dir.
  • change MainActivity.java and main.dart and AndroidManifest.xml like this

MyReceiver

    package com.example.flutter_broadcastreceiver_alarmmanager_repeat;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    public class MyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            MainActivity.callFlutter();
        }
    }

MainActivity

package com.example.flutter_broadcastreceiver_alarmmanager_repeat;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import io.flutter.app.FlutterActivity;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;
import io.flutter.view.FlutterView;

public class MainActivity extends FlutterActivity {

    private PendingIntent pendingIntent;
    private AlarmManager alarmManager;
    private static  FlutterView flutterView;
    private static final String CHANNEL = "com.tarazgroup";

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        flutterView=getFlutterView();
        GeneratedPluginRegistrant.registerWith(this);

        Intent intent = new Intent(this, MyReceiver.class);
        pendingIntent = PendingIntent.getBroadcast(this, 1019662, intent, 0);
        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 1000, pendingIntent);

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        alarmManager.cancel(pendingIntent);
    }

    static void callFlutter(){
        MethodChannel methodChannel=new MethodChannel(flutterView, CHANNEL);
        methodChannel.invokeMethod("I say hello every minute!!","");
    }
}

main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.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: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

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

class _MyHomePageState extends State<MyHomePage> {

  static const methodChannel = const MethodChannel('com.tarazgroup');

  _MyHomePageState() {
    methodChannel.setMethodCallHandler((call) {
      print(call.method);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
      ),
      body: Container() 
    );
  }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.flutter_broadcastreceiver_alarmmanager_repeat">

    <application
        android:name="io.flutter.app.FlutterApplication"
        android:icon="@mipmap/ic_launcher"
        android:label="flutter_broadcastreceiver_alarmmanager_repeat">
        <activity
            android:name=".MainActivity"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:windowSoftInputMode="adjustResize">

            <meta-data
                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
                android:value="true" />

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".MyReceiver"></receiver>

    </application>

</manifest>

your flutter code calls avery 1 min. even your app minimized or switch to another app or screen off.

Answer 3

This is a library to do just that background_fetch.

Background Fetch is a very simple plugin which will awaken an app in the background about every 15 minutes, providing a short period of background running-time. This plugin will execute your provided callbackFn whenever a background-fetch event occurs. ref

Answer 4

flutter_background_service combined with Timer from dart:async.

see :

• https://pub.dev/packages/flutter_background_service

Answer 5

Is it possible to do this kind of things with Flutter?

Yes, now the dart can run in the background by running the flutter engine within the native android service component. (original link)

NOTE: you cannot replace the native service component provided by android. Instead, you have to run the flutter engine within that service component.

You can manually do this as in this article : Article link

Or

You can use third-party packages, like work manager plugin