Navigator.PopまたはPushで状態を更新する方法

Question

ここでは、最初の2ページはBSP_signup_termsページと呼ばれ、2ページ目はBsp_Service_pageです。そのページのBSP_signup_termsにいるとき、選択したチェックボックスに基づいていくつかのチェックボックスを選択する必要があります。これにより、いくつかのデータが表示されます。しかし、問題は、完全なデータが表示されることですが、BSP_signup_termsからBsp_signup_pageに戻ってチェックボックスを変更し、次のボタンを押しても、結果は変わりません。前の結果と同じです。

これが出力ページの画像です

この画像では、チェックボックスを1つだけ選択すると、サービスページにいくつかの値が表示され、契約条件ページに戻って、さらに1つのチェックボックスを選択すると、両方の画面出力が添付されます。サービスページを更新しません

これが私が試したコードです

---

BSP_Signup_Terms_Page

class BspLicensedSignupTermsPage extends StatefulWidget {
  static const String routeName = "/bspLicensedSignupTerms";
  final BspSignupCommonModel bspSignupCommonModel;

  BspLicensedSignupTermsPage({
    Key key,
    @required this.bspSignupCommonModel,
  }) : super(key: key);

  @override
  _BspLicensedSignupTermsPageState createState() =>
      _BspLicensedSignupTermsPageState();
}

class _BspLicensedSignupTermsPageState
    extends State<BspLicensedSignupTermsPage> {
  @override
  void initState() {
    super.initState();
  }

  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
  bool _isWalkIn = false;
  bool _isHome = false;
  bool _isOnDemand = false;



  Widget _buildselectcheckbox() {
    return Text(
      AppConstantsValue.appConst['bsplicensedsignupterms']['selectcheck']
          ['translation'],
    );
  }

  // Walkin
  _onCustomerWalkin(value) {
    setState(() {
      _isWalkIn = value;
    });
  }

  Widget _buildCustomerWalkIn() {
    return TudoConditionWidget(
      text: AppConstantsValue.appConst['bsplicensedsignupterms']
          ['CustomerWalkIn']['translation'],
      onChanged: (value) {
        print(value);
        _onCustomerWalkin(value);
      },
      validate: false,
    );
  }


  // Home
  _onCustomerInHome(value) {
    setState(() {
      _isHome = value;
    });
  }

  Widget _buildCustomerInHome() {
    return TudoConditionWidget(
      text: AppConstantsValue.appConst['bsplicensedsignupterms']
          ['CustomerInHome']['translation'],
      onChanged: (value) {
        _onCustomerInHome(value);
      },
      validate: false,
    );
  }

  Widget _buildCustomerInHomeHelp() {
    return Text(
      AppConstantsValue.appConst['bsplicensedsignupterms']['businesscheckhelp']
          ['translation'],
    );
  }

  // On Demand

  _onCustomerOnDemand(value) {
    setState(() {
      _isOnDemand = value;
    });
  }

  Widget _buildBusinessOnDemand() {
    return TudoConditionWidget(
      text: AppConstantsValue.appConst['bsplicensedsignupterms']
          ['BusinessOnDemand']['translation'],
      onChanged: (value) {
        _onCustomerOnDemand(value);
      },
      validate: false,
    );
  }

  Widget _buildBusinessOnDemandHelp() {
    return Text(AppConstantsValue.appConst['bsplicensedsignupterms']
        ['businessprovidehelp']['translation']);
  }

  @override
  Widget build(BuildContext context) {
    final appBar = AppBar(
      title: Text("Bsp Licensed Signup Terms and Condition"),
      leading: IconButton(
        icon: Icon(Icons.arrow_back_ios),
        onPressed: () {
          NavigationHelper.navigatetoBack(context);
        },
      ),
      centerTitle: true,
    );

    final bottomNavigationBar = Container(
      height: 56,
      //margin: EdgeInsets.symmetric(vertical: 24, horizontal: 12),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: <Widget>[
          new FlatButton.icon(
            icon: Icon(Icons.close),
            label: Text('Clear'),
            color: Colors.redAccent,
            textColor: Colors.black,
            padding: EdgeInsets.symmetric(vertical: 10, horizontal: 30),
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(7),
            ),
            onPressed: () {
              _formKey.currentState.reset();
            },
          ),
          new FlatButton.icon(
            icon: Icon(FontAwesomeIcons.arrowCircleRight),
            label: Text('Next'),
            color: colorStyles["primary"],
            textColor: Colors.white,
            padding: EdgeInsets.symmetric(vertical: 10, horizontal: 30),
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(7),
            ),
            onPressed: () {
              if (_formKey.currentState.validate()) {
                if (_isHome == false &&
                    _isOnDemand == false &&
                    _isWalkIn == false) {
                  showDialog(
                      barrierDismissible: false,
                      context: context,
                      builder: (context) => ShowErrorDialog(
                            title: Text('Select Service'),
                            content: Text(
                              'Please select atleast one service type to proceed next',
                            ),
                          ));
                } else {
                  BspSignupCommonModel model = widget.bspSignupCommonModel;
                  model.isWalkin = _isWalkIn;
                  model.isHome = _isHome;
                  model.isOnDemand = _isOnDemand;
                  print(model.toJson());
                  Navigator.Push(
                    context,
                    MaterialPageRoute(
                      builder: (context) =>
                          BspServicePage(bspSignupCommonModel: model),
                    ),
                  );
                }
              }
            },
          ),
        ],
      ),
    );
    return new Scaffold(
      appBar: appBar,
      bottomNavigationBar: bottomNavigationBar,
      body: Container(
        height: double.infinity,
        width: double.infinity,
        child: Stack(
          children: <Widget>[

            SingleChildScrollView(
              child: SafeArea(

                child: Form(
                  autovalidate: true,
                  key: _formKey,
                  child: Scrollbar(
                    child: SingleChildScrollView(
                      dragStartBehavior: DragStartBehavior.down,
                      padding: const EdgeInsets.symmetric(horizontal: 10.0),
                      child: new Container(
                        decoration: BoxDecoration(
                            borderRadius: new BorderRadius.circular(25)),
                        child: new Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          crossAxisAlignment: CrossAxisAlignment.center,
                          children: [
                            _buildselectcheckbox(),
                            _buildCustomerWalkIn(),
                            _buildCustomerInHome(),
                            _buildCustomerInHomeHelp(),
                            _buildBusinessOnDemand(),
                            _buildBusinessOnDemandHelp(),
                          ],
                        ),
                      ),
                    ),
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

---

BSP_Service_Page

class BspServicePage extends StatefulWidget {
  static const String routeName = "/bspService";
  final BspSignupCommonModel bspSignupCommonModel;

  BspServicePage({
    Key key,
    @required this.bspSignupCommonModel,
  }) : super(key: key);

  @override
  _BspServicePageState createState() => _BspServicePageState();
}

class _BspServicePageState extends State<BspServicePage> {
  List<int> servicesIds = [];
  Map<String, bool> selection = {};
  List<BspServices.Service> selectedServices = [];
  SearchBarController _controller = new SearchBarController();
  String _searchText = '';
  bool refreshservices = true;

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

  void _showErrorDialog(String message) {
    showDialog(
      barrierDismissible: false,
      context: context,
      builder: (context) => ShowErrorDialog(
        title: Text('An Error Occurred!'),
        content: Text(message),
      ),
    );
  }

  void refresh() {
    setState(() {
      refreshservices = !refreshservices;
    });
  }

  @override
  Widget build(BuildContext context) {
    var _bspServiceBloc = new BspServiceBloc();
    final appBar = SearchBar(
      controller: _controller,
      onQueryChanged: (String query) {
        print('Search Query $query');
        setState(() {
          _searchText = query;
        });
      },
      defaultBar: AppBar(
        centerTitle: true,
        leading: IconButton(
            icon: Icon(Icons.arrow_back_ios),
            onPressed: () {
              refresh();
              NavigationHelper.navigatetoBack(context);
            }),
        title: Text('Select Services'),
      ),
    );

    final bottomNavigationBar = Container(
      height: 56,
      // margin: EdgeInsets.symmetric(vertical: 24, horizontal: 12),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: <Widget>[
          new FlatButton.icon(
            icon: Icon(Icons.close),
            label: Text('Clear'),
            color: Colors.redAccent,
            textColor: Colors.black,
            padding: EdgeInsets.symmetric(vertical: 10, horizontal: 30),
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(7),
            ),
            onPressed: () {
              print('reseting the state');
              setState(() {
                selection = {};
                servicesIds = [];
              });
            },
          ),
          new FlatButton.icon(
            icon: Icon(FontAwesomeIcons.arrowCircleRight),
            label: Text('Next'),
            color: colorStyles["primary"],
            textColor: Colors.white,
            padding: EdgeInsets.symmetric(vertical: 10, horizontal: 30),
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(7),
            ),
            onPressed: () {
              BspSignupCommonModel model = widget.bspSignupCommonModel;
              model.servicesIds = servicesIds;
              model.services = selectedServices;
              print('servicesIds at the next button');
              print(servicesIds);
              print(model.toJson());
              if (servicesIds.length == 0) {
                _showErrorDialog(
                    'You need to select at least one service to proceed next!');
              } else {
                Navigator.Push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => BusinessProfilePage(
                      bspSignupCommonModel: model,
                    ),
                  ),
                );
              }
            },
          ),
        ],
      ),
    );
    return new Scaffold(
      appBar: appBar,
      bottomNavigationBar: bottomNavigationBar,
      body: new BspServiceScreen(
        bspServiceBloc: _bspServiceBloc,
        bspSignupCommonModel: widget.bspSignupCommonModel,
        servicesIds: servicesIds,
        selection: selection,
        searchQuery: _searchText,
        selectedServices: selectedServices,
        refresh: refresh,
      ),
    );
  }
}

---

Bsp_service_screen

class BspServiceScreen extends StatefulWidget {
  final BspServiceBloc _bspServiceBloc;
  final String searchQuery;
  final List<int> servicesIds;
  final Map<String, bool> selection;
  final BspSignupCommonModel bspSignupCommonModel;
  final List<BspServices.Service> selectedServices;
  final Function refresh;

  const BspServiceScreen({
    Key key,
    @required BspServiceBloc bspServiceBloc,
    @required this.bspSignupCommonModel,
    @required this.servicesIds,
    @required this.selection,
    @required this.selectedServices,
    @required this.refresh,
    this.searchQuery,
  })  : _bspServiceBloc = bspServiceBloc,
        super(key: key);

  @override
  BspServiceScreenState createState() {
    return new BspServiceScreenState(_bspServiceBloc);
  }
}

class BspServiceScreenState extends State<BspServiceScreen> {
  final BspServiceBloc _bspServiceBloc;

  BspServiceScreenState(this._bspServiceBloc);
  // Map<String, bool> _selection = {};

  @override
  void initState() {
    super.initState();
    bool isHome = widget.bspSignupCommonModel.isHome;
    bool isWalkIn = widget.bspSignupCommonModel.isWalkin;
    bool isOnDemand = widget.bspSignupCommonModel.isOnDemand;
    this._bspServiceBloc.dispatch(LoadBspServiceEvent(
          countryId: 1,
          isHome: isHome,
          isOnDemand: isOnDemand,
          isWalkin: isWalkIn,
        ));
  }

  @override
  void dispose() {
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<BspServiceBloc, BspServiceState>(
      bloc: widget._bspServiceBloc,
      builder: (
        BuildContext context,
        BspServiceState currentState,
      ) {
        if (currentState is UnBspServiceState) {
          return Center(child: CircularProgressIndicator());
        }
        if (currentState is ErrorBspServiceState) {
          return new Container(
            child: new Center(
              child: new Text(currentState.errorMessage ?? 'Error'),
            ),
          );
        }
        if (currentState is InBspServiceState) {
          // print(
          //     'in bsp service state, ${currentState.bspServices.servicesByCountry.length}');
          if (currentState.bspServices.servicesByCountry.length == 0) {
            return Container(
              child: Center(
                child: Text("No Services available for this combination"),
              ),
            );
          } else {
            return new Container(
              child:
                  _renderServices(currentState.bspServices.servicesByCountry),
            );
          }
        }
        return Container();
      },
    );
  }

  List<ServicesByCountry> finalList = new List();

  ListView _renderServices(List<ServicesByCountry> lovCountryServices) {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (widget.searchQuery != '') {
        finalList.clear();
        lovCountryServices.forEach((ServicesByCountry data) {
          if (data.name
              .toLowerCase()
              .contains(widget.searchQuery.toLowerCase())) {
            setState(() {
              finalList.add(data);
            });
          } else {
            data.services.forEach((ServiceList.Service services) {
              if (services.name
                  .toLowerCase()
                  .contains(widget.searchQuery.toLowerCase())) {
                setState(() {
                  finalList.add(data);
                });
              }
            });
          }
        });
      } else {
        setState(() {
          finalList.clear();
          finalList.addAll(lovCountryServices);
        });
      }
    });
    return ListView.builder(
      shrinkWrap: true,
      padding: const EdgeInsets.all(8.0),
      itemCount: finalList.length,
      itemBuilder: (BuildContext context, int index) {
        ServicesByCountry item = finalList[index];
        List itemsList = item.services;
        return ExpansionTile(
          title: Text(item.name),
          children: List.generate(itemsList.length, (i) {
            widget.selection[itemsList[i].name] =
                widget.selection[itemsList[i].name] ?? itemsList[i].isSelected;
            return CheckboxListTile(
              title: Text(itemsList[i].name),
              value: widget.selection[itemsList[i].name],
              onChanged: (val) {
                setState(() {
                  widget.selection[itemsList[i].name] = val;
                  if (val) {
                    widget.servicesIds.add(itemsList[i].id);

                    List<BspServices.Service> services =
                        widget.selectedServices.where((service) {
                      return service.mainCategory == item.name;
                    }).toList();

                    SubCategory subService = new SubCategory(
                      id: itemsList[i].id,
                      name: itemsList[i].name,
                    );

                    List<SubCategory> subCategories = [];
                    if (services.length == 0) {
                      subCategories.add(subService);
                      widget.selectedServices.add(
                        new BspServices.Service(
                          mainCategory: item.name,
                          mainCategoryId: item.id,
                          subCategory: subCategories,
                        ),
                      );
                    } else {
                      print('services in else');
                      print(services[0].subCategory);
                      subCategories = services[0].subCategory;
                      subCategories.add(subService);
                    }
                  } else {
                    widget.servicesIds.removeWhere((service) {
                      return service == itemsList[i].id;
                    });

                    List<BspServices.Service> services =
                        widget.selectedServices.where((service) {
                      return service.mainCategory == item.name;
                    }).toList();

                    services[0].subCategory.removeWhere((subService) {
                      return subService.id == itemsList[i].id;
                    });
                  }
                });
                print('widget.servicesIds after set state');
                print(widget.servicesIds);
              },
            );
          }),
        );
      },
    );
  }
}

Answer 1

最初のページに戻ったら、setState（）を使用できます。

Navigator.Push(context, MaterialPageRoute(builder: (context) => Page2())).then((value) {
  setState(() {
    // refresh state
  });
});

Answer 2

以下のコードを試してください：-

まず、1つのメソッド非同期メソッドを追加します。

void redirectToNextScreen() async {
    final Route route = MaterialPageRoute(
        builder: (context) => BspServicePage(bspSignupCommonModel: model));
    final result = await Navigator.Push(mContext, route);
    try {
      if (result != null) {
        if (result) {
          //Return callback here.
        }
      }
    } catch (e) {
      print(e.toString());
    }
  }

次に、このメソッドを "BSP_Signup_Terms_Page" Next button Pressedイベントで呼び出すことができます。

次に、 "BspServicePage"画面NextおよびCancelイベントの行の下に追加できます。

Navigator.pop(mContext, true); //true means refresh back page and false means not refresh.