new Container(
height: 300.0,
color: Colors.transparent,
child: new Container(
decoration: new BoxDecoration(
color: Colors.green,
borderRadius: new BorderRadius.only(
topLeft: const Radius.circular(40.0),
topRight: const Radius.circular(40.0),
)
),
child: new Center(
child: new Text("Hi modal sheet"),
)
),
),