Sending your application to background when back button is pressed in flutter - dart

Question

Flutter code to send the app to background when back button is pressed. I want to minimize the app to background when i click the back button like home button does to apps and now when i click the back button it kills the app. I am using willPopScope to get it work but no help

Answer 1

I found this package on pub.dev and it worked well for me and it's easy to use
https://pub.dev/packages/move_to_background

Answer 2

03.2020 UPDATE
As #user1717750 wrote - The dart code remains the same, so it's:
var _androidAppRetain = MethodChannel("android_app_retain");
#override
Widget build(BuildContext context) {
return WillPopScope(
onWillPop: () {
if (Platform.isAndroid) {
if (Navigator.of(context).canPop()) {
return Future.value(true);
} else {
_androidAppRetain.invokeMethod("sendToBackground");
return Future.value(false);
}
} else {
return Future.value(true);
}
},
child: Scaffold(
...
),
);
}
The code in the MainActivity() should look like this:
class MainActivity: FlutterActivity() {
override fun configureFlutterEngine(#NonNull flutterEngine: FlutterEngine) {
GeneratedPluginRegistrant.registerWith(flutterEngine);
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, "android_app_retain").apply {
setMethodCallHandler { method, result ->
if (method.method == "sendToBackground") {
moveTaskToBack(true)
}
}
}
}
}

Answer 3

From here:
https://medium.com/stuart-engineering/%EF%B8%8F-the-tricky-task-of-keeping-flutter-running-on-android-2d51bbc60882
PLAT FORM CODE:
class MainActivity : FlutterActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
GeneratedPluginRegistrant.registerWith(this)
MethodChannel(flutterView, "android_app_retain").apply {
setMethodCallHandler { method, result ->
if (method.method == "sendToBackground") {
moveTaskToBack(true)
}
}
}
}
}
YOUR DART CODE:
Widget build(BuildContext context) {
return WillPopScope(
onWillPop: () {
if (Platform.isAndroid) {
if (Navigator.of(context).canPop()) {
return Future.value(true);
} else {
_androidAppRetain.invokeMethod("sendToBackground");
return Future.value(false);
}
} else {
return Future.value(true);
}
},
child: Scaffold(
drawer: MainDrawer(),
body: Stack(
children: <Widget>[
GoogleMap(),
],
),
),
);
}
CREDIT TO:
Sergi Castellsagué Millán