Show alert dialog on app main screen load automatically in flutter

Question

I want to show alert dialog based on a condition. Not based on user interaction such as button press event.

If a flag is set in app state data alert dialog is shown

Answer 1

I solved it using a package developed by Flutter Community. here https://pub.dev/packages/after_layout

Add this to your pubspec.yaml

after_layout: ^1.0.7+2

And try below example

import 'package:after_layout/after_layout.dart';
import 'package:flutter/material.dart';

class DialogDemo extends StatefulWidget {
  @override
  _DialogDemoState createState() => _DialogDemoState();
}

class _DialogDemoState extends State
    with AfterLayoutMixin {
  @override
  void initState() {
    super.initState();
  }

  @override
  void afterFirstLayout(BuildContext context) {
    _neverSatisfied();
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Container(
        decoration: BoxDecoration(color: Colors.red),
      ),
    );
  }

  Future _neverSatisfied() async {
    return showDialog(
      context: context,
      barrierDismissible: false, // user must tap button!
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Rewind and remember'),
          content: SingleChildScrollView(
            child: ListBody(
              children: [
                Text('You will never be satisfied.'),
                Text('You\’re like me. I’m never satisfied.'),
              ],
            ),
          ),
          actions: [
            FlatButton(
              child: Text('Regret'),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }
}