Container, shape and Expanded

demo7_container_shape.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(home: MyApp()));
}

void pn(num n) => print(n);

// Column -> container
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Widget scaffold = Scaffold(
      appBar: AppBar(title: Text("My App")),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
//        crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            Expanded(
              flex: 2,
              child: Container(
                width: 100.0,
                height: 100.0,
                decoration: BoxDecoration(
                  color: Colors.blue,
                  shape: BoxShape.rectangle,
                ),
                alignment: Alignment.center,
                // child的對齊
                child: Icon(Icons.home, color: Colors.white),
              ),
            ),
            Expanded(
              child: Container(
                width: 100.0,
                height: 100.0,
                margin: EdgeInsets.only(top: 10),
                decoration: BoxDecoration(
                  color: Colors.green,
                  shape: BoxShape.rectangle,
                ),
                alignment: Alignment.center,
                // child的對齊
                child: Icon(Icons.keyboard, color: Colors.white),
              ),
            ),
            Container(
              width: 100.0,
              height: 100.0,
              margin: EdgeInsets.only(top: 10),
              decoration: BoxDecoration(
                color: Colors.red,
                shape: BoxShape.circle,
              ),
              alignment: Alignment.center,
              // child的對齊
              child: Icon(Icons.schedule, color: Colors.white),
            ),
          ],
        ),
      ),
    );

    return scaffold;
  }
}