Call Flutter Function from Android Part of the App

Question

I have an Android app that uses Flutter/Dart as a library.

When the app is closed it continues to run in the background as a service. In the Android code (in Java), I need to call a method that is written in the Flutter part of the app.

How can I do that? I found some posts mentioning the MethodChannel but I only found examples where the Flutter part calls a method from the native (Android) part. I want to do the opposite.

How can I do that?

Thank you.

Answer 1

in Flutter, after creating MethodChannel instance, attach a MethodCallHandler like this:

_channel.setMethodCallHandler((call){
      print(call.method);
    });

And from your Android code do this:

channel.invokeMethod("hello","any argument");

However, it will not work when the app has been terminated even if a service is still alive. I have tested it.