flutter close show dialog code example

Example 1: flutter close dialog

showDialog(
    context: context,
    builder: (_) {
      return AlertDialog(
        title: Text('Wanna Exit?'),
        actions: [
          FlatButton(
            onPressed: () => Navigator.pop(context, false), // passing false
            child: Text('No'),
          ),
          FlatButton(
            onPressed: () => Navigator.pop(context, true), // passing true
            child: Text('Yes'),
          ),
        ],
      );
    }).then((exit) {
  if (exit == null) return;

  if (exit) {
    // user pressed Yes button
  } else {
    // user pressed No button
  }
});

Example 2: flutter show dialog on start

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

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

  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
          title: 'Trial',
          home: Scaffold(
              appBar: AppBar(title: Text('List scroll')), body: new MyHome()));
    }
  }

  class MyHome extends StatelessWidget { // Wrapper Widget
    @override
    Widget build(BuildContext context) {
      Future.delayed(Duration.zero, () => showAlert(context));
      return Container(
        child: Text("Hello world"),
      );
    }

    void showAlert(BuildContext context) {
      showDialog(
          context: context,
          builder: (context) => AlertDialog(
                content: Text("hi"),
              ));
    }
  }