refresh_indicator.dart

 @override
  void initState() {
    super.initState();
    random = Random();
    refreshList();
  }

  Future<Null> refreshList() async {
    refreshKey.currentState?.show();
    await Future.delayed(Duration(seconds: 2));
    setState(() {
      list = List.generate(random.nextInt(10), (i) => "Item $i");
    });
    return null;
  }