Flutter
ScaffoldMessenger
Show a SnackBar with ScaffoldMessenger.
What is ScaffoldMessenger?
ScaffoldMessenger is the structure used to show a SnackBar. With ScaffoldMessenger.of(context).showSnackBar(...) you display a brief info message. The SnackBar appears at the bottom of the screen and disappears on its own after a few seconds.
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Kaydedildi')),
);
Unlike a modal dialog, this approach does not interrupt the user's flow.
SnackBar content
The content parameter of SnackBar takes the widget to display; usually a Text. The duration parameter sets how long the message stays visible; the default is about four seconds.
SnackBar(
content: const Text('İşlem başarılı'),
duration: const Duration(seconds: 2),
)
This widget is shown in the bottom bar managed by ScaffoldMessenger.
Exercise Show a SnackBar
Define a StatelessWidget named BildirimButon. Its build should return an ElevatedButton whose onPressed calls ScaffoldMessenger.of(context).showSnackBar(...). The SnackBar's content should be Text('Kaydedildi'). Print 'hazir' in main.
Show example solution
import 'package:flutter/material.dart';
class BildirimButon extends StatelessWidget {
const BildirimButon({super.key});
@override
Widget build(BuildContext context) {
return ElevatedButton(
onPressed: () {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('Kaydedildi')),
);
},
child: const Text('Kaydet'),
);
}
}
void main() {
print('hazir');
}
Test yourself
-
What does ScaffoldMessenger.of(context).showSnackBar display?
- A SnackBar
- An AlertDialog
- A ModalBottomSheet
- A Drawer
Show answer
A SnackBar — showSnackBar displays a SnackBar; a brief bottom info message. AlertDialog is for dialogs, ModalBottomSheet is for bottom sheets, and Drawer is for side menus; showSnackBar does not display these.
-
ScaffoldMessenger access
____.of(context).showSnackBar(
SnackBar(content: Text('Kaydedildi')),
);
Show answer
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Kaydedildi')),
);
-
ScaffoldMessenger parts
- ScaffoldMessenger
- Message manager
- showSnackBar
- Method to show a message
- SnackBar
- Bottom info bar
- content
- Message content
Next lesson: ModalBottomSheet
