Flutter

TL;DR

What: Google’s UI toolkit for building natively compiled applications.

Why: Single codebase for iOS/Android/Web/Desktop, hot reload, beautiful UIs, great performance.

Quick Start

Install: Follow flutter.dev/docs/get-started/install

Verify:

flutter doctor

Create new app:

flutter create my_app
cd my_app
flutter run

Cheatsheet

Command	Description
flutter create name	Create new project
flutter run	Run on device/emulator
flutter build apk	Build Android APK
flutter build ios	Build iOS app
flutter pub get	Get dependencies
flutter pub add pkg	Add package
flutter test	Run tests

Gotchas

Basic widget

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('My App')),
        body: const Center(child: Text('Hello, Flutter!')),
      ),
    );
  }
}

Stateful widget

class Counter extends StatefulWidget {
  @override
  _CounterState createState() => _CounterState();
}

class _CounterState extends State<Counter> {
  int _count = 0;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Count: $_count'),
        ElevatedButton(
          onPressed: () => setState(() => _count++),
          child: const Text('Increment'),
        ),
      ],
    );
  }
}

Common widgets

// Layout
Column(children: [...])
Row(children: [...])
Container(padding: ..., child: ...)
ListView.builder(itemBuilder: ...)

// Input
TextField(controller: ..., onChanged: ...)
ElevatedButton(onPressed: ..., child: ...)

// Display
Text('Hello')
Image.network('url')
Icon(Icons.star)

Navigation

// Push
Navigator.push(context, MaterialPageRoute(builder: (context) => NextPage()));

// Pop
Navigator.pop(context);

// Named routes
Navigator.pushNamed(context, '/details');

Next Steps

• Flutter Documentation - Official docs
• Flutter Cookbook - Recipes
• pub.dev - Package repository
• Flutter Samples - Examples