refresh_indicator.dart

 @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Hala para refrescar"),
      ),
      body: list != null
        ? RefreshIndicator(
        key: refreshKey,
        child: ListView.builder(
          itemCount: list.length,
          itemBuilder: (context, i) => ListTile(
            title: Text(list[i]),
          ),
        ),
        onRefresh: refreshList,
      ) : Center(child: CircularProgressIndicator()),
    );
  }