RaisedButton( onPressed: () {}, color: Colors.amber, shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(10)), child: Text("Click This"), )
shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(18.0), side: BorderSide(color: Colors.red) ),
FlatButton( color: Colors.red, shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(18.0)), child: new Text('round button'), onPressed: () {}, ),