Coding All-in-One For Dummies, 2nd Edition

Chapter 3

“Hello” from Flutter

IN THIS CHAPTER

Running your first Flutter app

Adding text and images

Improving your app's layout

♪ “Hello, I Must Be Going” ♪

BERT KALMAR AND HARRY RUBY, SUNG BY GROUCHO MARX, IN ANIMAL CRACKERS, 1930

According to legend, the first computer program to print nothing but “Hello world!” was written by Brian Kernighan, as part of the BCPL programming language documentation. The first public appearance of such a program was in Kernighan and Ritchie's 1972 book, The C Programming Language. Nowadays, the term Hello world program, or simply Hello program, applies to any dirt-simple code for someone’s first exposure to a new language or new framework.

This chapter features a simple “Hello world” Flutter program and several embellishments. You can run the code, dissect it, change it, and have fun with it.

First Things First: Creating a Flutter Project

Listing 3-1 contains your first Flutter app.

LISTING 3-1: Ahoy, Maties!

import 'package:flutter/material.dart';main() => runApp(App0301());class App0301 extends StatelessWidget { Widget build(BuildContext context) { return MaterialApp( home: Material( child: Text("Hello world!"), ), ); }}

Follow these steps ...