How to use Flutter Method Channel in background (app minimised/closed)

Question

I am working on a native Android widget in a Flutter App. In which there is refresh button, on click of that I have to call a method in the Flutter code. I am using Flutter

Answer 1

I am collecting information/discussion that redirects us to run flutter engine in background.

void callbackDispatcher() {
WidgetsFlutterBinding.ensureInitialized();
print("Our background job ran!");

}

void main() {

 static const MethodChannel _channel = const MethodChannel("channel-name");

 Future<void> initialize(final Function callbackDispatcher) async {

  final callback = PluginUtilities.getCallbackHandle(callbackDispatcher);

 await _channel.invokeMethod('initialize', callback.toRawHandle());
 }
}

As stated here How to run Flutter in the background?

When a background job is started by native the Flutter engine is not active. So we are unable to run Dart. Can Android/iOS starts the Flutter engine in the background? Yes! We’ll first need to register a Dart callback function which will only be invoked whenever a background job is started by the native code. This callback function is referred to as a callbackDispatcher.

Also please check out these stackoverflow discussions.

Flutter : Run an app as a background service

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

How to create a Flutter background service that works also when app closed

Executing Dart in the Background with Flutter Plugins and Geofencing

Answer 2

You may start the Flutter Engine in the background by register a Dart callback function which will only be invoked whenever a background job is started in Flutter.

Try this. https://medium.com/vrt-digital-studio/flutter-workmanager-81e0cfbd6f6e