import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      home: new ContainerDemo(),
    );
  }
}

class ContainerDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Center(
      child: new Container(
        width: 128.0,
        height: 128.0,
        decoration: new BoxDecoration(
          color: Colors.lightBlueAccent[100],
        ),
      ),
    );
  }
}

---

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      home: new ContainerDemo(),
    );
  }
}

class ContainerDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Center(
      child: new Container(
        width: 300.0,
        height: 400.0,
        decoration: new BoxDecoration(
          color: const Color(0xfffce5cd),
          border: new Border.all(
            color: const Color(0xff6d9eeb),
            width: 8.0,
          ),
        ),
        child: new Text('容器演示'),
      ),
    );
  }
}

---

本文参考