Flutter Page View dispose children，如何留住children和bloc

Question

I have the next structure of code and any time when I swipe to the next page, pageview distroy previos page(widget and bloc)
home: SafeArea( child: PageView(controller: _pageController, children: [ Scaffold( body: BlocProvider<Bloc>( bloc: bloc, child: Container()), Scaffold( body: BlocProvider<Bloc>( bloc: bloc, child: Container()) Scaffold( body: BlocProvider<Bloc>( bloc: bloc, child: Container()))) How can I save bloc class with a widget when pageview changes pages?

Answer 1

children of PageView need is a StatefullWidget and State of StatefullWidget is add with AutomaticKeepAliveClientMixin

Example :

class _SearchPageState extends State<SearchPage>
    with AutomaticKeepAliveClientMixin {
  static const TAG = 'SearchPage';

  VoidCallback onTapSort, onTapArea, onTapDatePicker, onTapFilter;

  SearchPageFilter searchFilter;

  WorkBloc _workBloc;

  VoidCallback onReloadPage;

  @override
  void initState() {
    super.initState();

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return ChangeNotifierProvider.value(
      value: searchFilter,
      child: Scaffold(
        appBar: AppBar(
          title: Text(AppLocalizations.of(context).titleSearchPage),
          bottom: PreferredSize(
              child: SearchSliverPersistentHeaderDelegate(
                  onTapSort, onTapArea,
                  onTapDatePicker: onTapDatePicker,
                  onTapFilter: onTapFilter),
              preferredSize: Size.fromHeight(128)),
        ),
        body: Builder(
            builder: (context) {
              //.....
            }
        ),
      ),
    );
  }

  @override
  bool get wantKeepAlive => true;
}