Flutter first attempt

1. Create a test application of Flutter

Directory lib / main.dart

Code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Welcome to Flutter',
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text('Welcome to Flutter'),
        ),
        body: new Center(
          child: new Text('Hello World'),
        ),
      ),
    );
  }
}

Description:

• This example creates a Material APP. Material is a standard web end and the movable end visual design language. Flutter provides a rich set of Material widgets.

• using the main function ( =>) symbol, which is the one-way function or method Dart shorthand.

• The application inherits StatelessWidget, which will make the application itself has become a widget. In Flutter, most things are widget, comprising alignment (Alignment), padding (padding) and layout (layout)

• Scaffold is a widget Material library provided, which provides a default navigation bar, and the title attribute contains the body home screen widget tree. widget tree can be very complex.

• The main widget is to provide a build () method to describe how to display themselves in accordance with other lower-level widget.

• The body of the present example includes a widget tree widget in Center, Center widget further comprises a sub-Text widget. Center widget its child widget tree to the center of the screen it can be.