Flutter -- iOS -- Center

import 'package:flutter/material.dart';

void main() => runApp(
  new MaterialApp(
    title: 'Center居中布局',
    home: new LayoutDemo(),
  ),
);

class LayoutDemo extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return  new Scaffold(
      appBar: new AppBar(
        title: new Text('iOS 导航栏'),
      ),
      body: new Center(
        child: new Text(
          'Hello Flutter',
          style: TextStyle(
            fontSize: 36.0,
          ),
        ),
      ),
    );
  }
}