Vfrdtyky

Can I create something similar to Toasts in Flutter ? Just a tiny notification window that is not directly in the face of the user and does not lock or fade the view behind it?

You can access the parent ScaffoldState using Scaffold.of(context)

Then do something like

Scaffold.of(context).showSnackBar(new SnackBar(

      content: new Text("Sending Message"),

    ));

Snackbars are the official "Toast" from material design. See https://material.io/design/components/snackbars.html#usage

Here is a fully working example:

import 'package:flutter/material.dart';



void main() {

  runApp(MyApp());

}



class MyApp extends StatelessWidget {

  @override

  Widget build(BuildContext context) {

    return MaterialApp(

      home: const Home(),

    );

  }

}



class Home extends StatelessWidget {

  const Home({

    Key key,

  }) : super(key: key);



  @override

  Widget build(BuildContext context) {

    return Scaffold(

      appBar: AppBar(

        title: const Text('Snack bar'),

      ),



      /// We use [Builder] here to use a [context] that is a descendant of [Scaffold]

      /// or else [Scaffold.of] will return null

      body: Builder(

        builder: (context) => Center(

              child: RaisedButton(

                child: const Text('Show toast'),

                onPressed: () => _showToast(context),

              ),

            ),

      ),

    );

  }



  void _showToast(BuildContext context) {

    final scaffold = Scaffold.of(context);

    scaffold.showSnackBar(

      SnackBar(

        content: const Text('Added to favorite'),

        action: SnackBarAction(

            label: 'UNDO', onPressed: scaffold.hideCurrentSnackBar),

      ),

    );

  }

}

SnackBar is definitely the right class to use, as pointed out by Darky.

One tricky thing about showSnackBar is getting to the ScaffoldState, if you're trying to call showSnackBar within the build method where you construct your Scaffold.

You might see an error like this, which includes some text explaining how to solve the problem.

══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════

The following assertion was thrown while handling a gesture:

Scaffold.of() called with a context that does not contain a Scaffold.

No Scaffold ancestor could be found starting from the context that was passed to Scaffold.of(). This

usually happens when the context provided is from the same StatefulWidget as that whose build

function actually creates the Scaffold widget being sought.

There are several ways to avoid this problem. The simplest is to use a Builder to get a context that

is "under" the Scaffold. For an example of this, please see the documentation for Scaffold.of():

  https://docs.flutter.io/flutter/material/Scaffold/of.html

A more efficient solution is to split your build function into several widgets. This introduces a

new context from which you can obtain the Scaffold. In this solution, you would have an outer widget

that creates the Scaffold populated by instances of your new inner widgets, and then in these inner

widgets you would use Scaffold.of().

A less elegant but more expedient solution is assign a GlobalKey to the Scaffold, then use the

key.currentState property to obtain the ScaffoldState rather than using the Scaffold.of() function.

The context used was:

  MyHomePage

When the exception was thrown, this was the stack:

#0      Scaffold.of (package:flutter/src/material/scaffold.dart:444:5)

#1      MyHomePage.build.<anonymous closure> (/Users/jackson/Library/Developer/CoreSimulator/Devices/7072C907-DBAD-44FE-8F40-0257442C51D9/data/Containers/Data/Application/77FEC1A4-1453-442C-8208-96E0323DEFB2/tmp/so_scratch2Tkq9Jb/so_scratch2/lib/main.dart:23:24)

#2      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:323:14)

#3      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:375:30)

#4      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)

#5      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:149:9)

#6      TapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:119:7)

#7      GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)

#8      BindingBase&SchedulerBinding&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:147:20)

#9      BindingBase&SchedulerBinding&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)

#10     BindingBase&SchedulerBinding&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)

#11     BindingBase&SchedulerBinding&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)

#12     BindingBase&SchedulerBinding&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)

#13     _invoke1 (file:///b/build/slave/Mac_Engine/build/src/flutter/lib/ui/hooks.dart:100)

#14     _dispatchPointerDataPacket (file:///b/build/slave/Mac_Engine/build/src/flutter/lib/ui/hooks.dart:58)

Handler: onTap

Recognizer:

  TapGestureRecognizer#69dbc(debugOwner: GestureDetector, state: ready)

════════════════════════════════════════════════════════════════════════════════════════════════════

You can either pass a GlobalKey to your Scaffold constructor:

class MyHomePage extends StatelessWidget {

  @override

  Widget build(BuildContext context) {

    final key = new GlobalKey<ScaffoldState>();

    return new Scaffold(

      key: key,

      floatingActionButton: new Builder(

        builder: (BuildContext context) {

          return new FloatingActionButton(

            onPressed: () {

              key.currentState.showSnackBar(new SnackBar(

                content: new Text("Sending Message"),

              ));

            },

            tooltip: 'Increment',

            child: new Icon(Icons.add),

          );

        }

      ),

    );

  }

}

Or you can use a Builder to create a BuildContext that is a child of the Scaffold.

class MyHomePage extends StatelessWidget {

  @override

  Widget build(BuildContext context) {

    return new Scaffold(

      floatingActionButton: new Builder(

        builder: (BuildContext context) {

          return new FloatingActionButton(

            onPressed: () {

              Scaffold.of(context).showSnackBar(new SnackBar(

                content: new Text("Sending Message"),

              ));

            },

            tooltip: 'Increment',

            child: new Icon(Icons.add),

          );

        }

      ),

    );

  }

}

Finally, you could split your widget into multiple classes, which is the best long-term approach.

use this plugin

Fluttertoast.showToast(

        msg: "This is Toast messaget",

        toastLength: Toast.LENGTH_SHORT,

        gravity: ToastGravity.CENTER,

        timeInSecForIos: 1

    );

to show toast message you can use flutterToast plugin to use this plugin you have to

1. Add this dependency to your pubspec.yaml file :- fluttertoast: ^2.0.7
   


2. to get the package you have to run this command :- $ flutter packages get
   


3. import the package :- import 'package:fluttertoast/fluttertoast.dart';
   

use it like this

Fluttertoast.showToast(

        msg: "your message",

        toastLength: Toast.LENGTH_SHORT,

        gravity: ToastGravity.BOTTOM // also possible "TOP" and "CENTER"

        bgcolor: "#e74c3c",

        textcolor: '#ffffff');

For more info check this