content: import 'package:flutter/material.dart';
  
  main() => runApp(new ContainerWidget());
  
  class ContainerWidget extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return new MaterialApp(
          title: 'Test',
          home: new Scaffold(
              appBar:
                  new AppBar(title: new Text('Flutter 容器Widget -- Container')),
              body: Container(
                margin: EdgeInsets.only(top: 50.0, left: 120.0), //容器外补白
                constraints:
                    BoxConstraints.tightFor(width: 200.0, height: 150.0), //卡片大小
                decoration: BoxDecoration(
                    //背景装饰
                    gradient: RadialGradient(
                        //背景径向渐变
                        colors: [Colors.green, Colors.blue],
                        center: Alignment.topLeft,
                        radius: .98),
                    boxShadow: [
                      //卡片阴影
                      BoxShadow(
                          color: Colors.black54,
                          offset: Offset(2.0, 2.0),
                          blurRadius: 4.0)
                    ]),
                transform: Matrix4.rotationZ(.2), //卡片倾斜变换
                alignment: Alignment.center, //卡片内文字居中
                child: Text(
                  //卡片文字
                  "Hello Flutter",
                  style: TextStyle(color: Colors.white, fontSize: 40.0),
                ),
              )));
    }
  }
  