flutter Stack

class StackWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Stack(
      children: <Widget>[
        Container(color: Colors.purple,width: 200,height: 200,),
        Positioned(
          left: 20,
          top: 20,
          child: Icon(Icons.pets,size: 50,color: Colors.red,),
        ),
        Positioned(
          bottom: 20,
          right: 20,
          child: Text("你好 Roy",style: TextStyle(fontSize: 20,color: Colors.blue),),
        ),
      ],
    );
  }
}