Open a modal or a dialogue after navigation in Flutter

Question

After calling Navigator pushReplacement, I arrive at a screen where I'd like to open a modal or a dialog automatically after the screen loads. I'm trying to do that using Timer.run inside initState() but it doesn't work, it doesn't show any errors as well. Could anyone help me understand what am I missing here?

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'dart:async';

class AfterSplash extends StatefulWidget {
  @override
  _AfterSplashState createState() => _AfterSplashState();
}

class _AfterSplashState extends State<AfterSplash> {
  void initState() {
    super.initState();
    Timer.run(() {
      showDialog(
        context: context,
        builder: (_) => AlertDialog(title: Text("Dialog title")),
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    return opacityLogoTitle();
  }
}

Widget opacityLogoTitle() {
  return Scaffold(
    body: Opacity(
      opacity: 0.5,
      child: Scaffold(
        body: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Center(
              child: Padding(
                padding: const EdgeInsets.all(20.0),
                child: Container(
                  child: Image(image: AssetImage('assets/images/main.png')),
                ),
              ),
            ),
            Text(
              'Sample App',
              style: TextStyle(
                fontFamily: 'SF Pro Display',
                fontSize: 60,
                color: Color.fromRGBO(105, 121, 248, 1),
              ),
            ),
          ],
        ),
      ),
    ),
  );
}

Solution

It's my test code with your code.
It works well.

import 'dart:async';

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: AfterSplash(),
      floatingActionButton: FloatingActionButton(
        onPressed: () {},
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

class AfterSplash extends StatefulWidget {
  @override
  _AfterSplashState createState() => _AfterSplashState();
}

class _AfterSplashState extends State<AfterSplash> {
  void initState() {
    super.initState();
    Timer.run(() {
      showDialog(
        context: context,
        builder: (_) => AlertDialog(title: Text("Dialog title")),
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    return opacityLogoTitle();
  }
}

Widget opacityLogoTitle() {
  return Scaffold(
    body: Opacity(
      opacity: 0.5,
      child: Scaffold(
        body: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Center(
              child: Padding(
                padding: const EdgeInsets.all(20.0),
                child: Container(child: Text('asdf')),
              ),
            ),
            Text(
              'Sample App',
              style: TextStyle(
                fontFamily: 'SF Pro Display',
                fontSize: 60,
                color: Color.fromRGBO(105, 121, 248, 1),
              ),
            ),
          ],
        ),
      ),
    ),
  );
}

Comments

[Abhijith]

I have tested this code with dartpad ,like user KuKu said it works fine@gogolism

[Admin]

Does work now. Thanks for the code. Another problem I found in my code was the inconsistent use of Material & Cupertino widgets. As I replaced all Cupertino with Material ones, it started working.