Snackbar is displayed after tapping back button - flutter

Question

Flow is: user clicks on a link from screen 1 to go to screen 2. On screen 2, user enters required data and taps on save button that saves data and navigates to screen 1 where I want to show a snackbar.
This sounds very similar to this and this post, but it's not working for me. So, I followed this code sample which works properly, but there's one issue.
If I press app bar back button or device back button from screen 2, it still shows the snackbar on screen 1. Wondering how could I avoid this behavior of not showing snackbar after hitting back buttons.
After user saves data on screen 2, I am simply using Navigator.pop(context) that takes user to screen 1. On screen 1, I've a method that navigates to screen 2 and triggers snackbar as below:
Navigator.push(
context, MaterialPageRoute(builder: (context) => Screen2())
);
scaffoldKey.currentState.showSnackBar(SnackBar(content: Text('Show me'),));
Although this works, I don't want to show the snackbar if user clicks back button.

Answer 1

Problem is, your snackBar has duration, within that duration if you navigate back to the screen, you'll see that old snackBar again.
Solution is add this method before Navigator:
Scaffold.of(context).removeCurrentSnackBar();
In your case, you're using scaffoldKey, so translate it as you need. But, be sure you are contacting with right Scaffold.
scaffoldKey.currentState.removeCurrentSnackBar();
Official link:
https://api.flutter.dev/flutter/material/ScaffoldState/removeCurrentSnackBar.html
Edit: About calling Screen 1 Scaffold inside Screen 2 Scaffold:
Your screen has Scaffolds. Scaffolds have keys in your situation as I see.
Let's say Screen1 has screen1Key ScaffoldState key. Same for Screen2.
Inside Screen2 you must call
screen1Key.currentState.removeCurrentSnackBar();
full example:
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(
home: Screen1(),
));
}
GlobalKey<ScaffoldState> screen1Key = GlobalKey<ScaffoldState>();
GlobalKey<ScaffoldState> screen2Key = GlobalKey<ScaffoldState>();
class Screen1 extends StatefulWidget {
#override
_Screen1State createState() => _Screen1State();
}
class _Screen1State extends State<Screen1> {
#override
Widget build(BuildContext context) {
return Scaffold(
key: screen1Key,
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
RaisedButton(
onPressed: () {
screen1Key.currentState
.showSnackBar(SnackBar(content: Text('Screen 1 SnackBar')));
},
child: Text('Show SnackBar'),
),
RaisedButton(
onPressed: () {
Navigator.push(context, MaterialPageRoute(builder: (context) {
return Screen2();
}));
},
child: Text('Navigate forward'),
),
],
),
),
);
}
}
class Screen2 extends StatefulWidget {
#override
_Screen2State createState() => _Screen2State();
}
class _Screen2State extends State<Screen2> {
#override
Widget build(BuildContext context) {
return Scaffold(
key: screen2Key,
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
RaisedButton(
onPressed: () {
screen2Key.currentState
.showSnackBar(SnackBar(content: Text('Screen 2 SnackBar')));
},
child: Text('Show SnackBar'),
),
RaisedButton(
onPressed: () {
screen1Key.currentState.removeCurrentSnackBar();
Navigator.pop(context);
},
child: Text('Navigate Back'),
),
],
),
),
);
}
}
I hope I understand well your problem.