У меня есть 5 меню в BottomNavigationBar. Когда я переключаюсь с одного на другое, иногда я получаю сообщение об ошибке вроде

E/flutter (13314): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: setState() called after dispose(): _PromoProductState#a00c8(lifecycle state: defunct, not mounted)
E/flutter (13314): This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code calls setState() from a timer or an animation callback.
E/flutter (13314): The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
E/flutter (13314): This error might indicate a memory leak if setState() is being called because another object is retaining a reference to this State object after it has been removed from the tree. To avoid memory leaks, consider breaking the reference to this object during dispose().
E/flutter (13314): #0      State.setState.<anonymous closure> 
package:flutter/…/widgets/framework.dart:1112
E/flutter (13314): #1      State.setState 
package:flutter/…/widgets/framework.dart:1147
E/flutter (13314): #2      _PromoProductState.initState.<anonymous closure> 
package:tokopedia/widgets/promo_product.dart:16
E/flutter (13314): #3      _rootRun  (dart:async/zone.dart:1122:38)
E/flutter (13314): #4      _CustomZone.run  (dart:async/zone.dart:1023:19)
E/flutter (13314): #5      _CustomZone.runGuarded  (dart:async/zone.dart:925:7)
E/flutter (13314): #6      _CustomZone.bindCallbackGuarded.<anonymous closure>  (dart:async/zone.dart:965:23)
E/flutter (13314): #7      _rootRun  (dart:async/zone.dart:1126:13)
E/flutter (13314): #8      _CustomZone.run  (dart:async/zone.dart:1023:19)
E/flutter (13314): #9      _CustomZone.bindCallback.<anonymous closure>  (dart:async/zone.dart:949:23)
E/flutter (13314): #10     Timer._createTimer.<anonymous closure>  (dart:async-patch/timer_patch.dart:23:15)
E/flutter (13314): #11     _Timer._runTimers  (dart:isolate-patch/timer_impl.dart:384:19)
E/flutter (13314): #12     _Timer._handleMessage  (dart:isolate-patch/timer_impl.dart:418:5)
E/flutter (13314): #13     _RawReceivePortImpl._handleMessage  (dart:isolate-patch/isolate_patch.dart:174:12)

Это происходит только в том случае, если я перехожу (быстро) из другого меню в home menu, который содержит статические данные (пока не вызывает api).

Я думаю, может быть, этот код проблема

@override
void initState() {
  Provider.of<LoadingState>(context, listen: false).setLoading = 0;
  Timer(Duration(seconds: 1), () {
    setState(() {
      time = time.add(Duration(seconds: -1));
    });
  });
  super.initState();
  listBottomWidget.add(HomeTab());
  listBottomWidget.add(FeedTab());
  listBottomWidget.add(InboxTab());
  listBottomWidget.add(CartTab());
  listBottomWidget.add(AccountTab());
}

Но я точно не знаю

Сообщение об ошибке отображается только при переключении на HomeTab().

Вот мой дом.дарт

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:badges/badges.dart';
import 'package:provider/provider.dart';
import 'package:tokopedia/providers/loading_state.dart';
import 'package:tokopedia/view/tabs/tab_account.dart';
import 'package:tokopedia/view/tabs/tab_cart.dart';
import 'package:tokopedia/view/tabs/tab_feed.dart';
import 'package:tokopedia/view/tabs/tab_home.dart';
import 'package:tokopedia/view/tabs/tab_inbox.dart';

class HomePage extends StatefulWidget {
  @override
  State createState() => HomePageState();
}

class HomePageState extends State<HomePage> {
  DateTime time = DateTime.now();
  int selectedPosition = 0;
  List<Widget> listBottomWidget = new List();

  @override
  void initState() {
    Provider.of<LoadingState>(context, listen: false).setLoading = 0;
    Timer(Duration(seconds: 1), () {
      setState(() {
        time = time.add(Duration(seconds: -1));
      });
    });
    super.initState();
    listBottomWidget.add(HomeTab());
    listBottomWidget.add(FeedTab());
    listBottomWidget.add(InboxTab());
    listBottomWidget.add(CartTab());
    listBottomWidget.add(AccountTab());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.white,
        title: Row(
          children: <Widget>[
            Container(
              padding: EdgeInsets.only(right: 12.0),
              child: Image.asset(
                "assets/images/qrcode.png",
                width: 30,
                height: 30,
              ),
            ),
            Expanded(
              child: Container(
                padding: EdgeInsets.only(right: 8.0),
                decoration: BoxDecoration(
                  color: Colors.grey[100],
                  borderRadius: BorderRadius.all(
                    Radius.circular(5.0),
                  ),
                ),
                child: TextField(
                  decoration: const InputDecoration(
                    prefixIcon: Icon(
                      Icons.search,
                      color: Colors.grey,
                    ),
                    border: InputBorder.none,
                    hintText: 'What you need?',
                  ),
                  style: TextStyle(
                    fontSize: 16,
                  ),
                ),
              ),
            ),
          ],
        ),
        actions: <Widget>[
          BadgeIconButton(
            itemCount: 0,
            icon: Icon(
              Icons.favorite,
              size: 28.0,
              color: Colors.grey[400],
            ),
            badgeColor: Colors.red,
            badgeTextColor: Colors.white,
            hideZeroCount: true,
            onPressed: () {},
          ),
          BadgeIconButton(
            itemCount: 4,
            icon: Icon(
              Icons.notifications,
              size: 28.0,
              color: Colors.grey[400],
            ),
            badgeColor: Colors.red,
            badgeTextColor: Colors.white,
            hideZeroCount: true,
            onPressed: () {},
          ),
        ],
      ),
      body: Builder(
        builder: (context) {
          return listBottomWidget[selectedPosition];
        },
      ),
      bottomNavigationBar: BottomNavigationBar(
        type: BottomNavigationBarType.fixed,
        currentIndex: selectedPosition, // this will be set when a tab is tapped
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            title: Text('Home'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.book),
            title: Text('Feed'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.mail),
            title: Text('Inbox'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.shopping_cart),
            title: Text('Cart'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.people),
            title: Text('Account'),
          ),
        ],
        onTap: (position) {
          setState(() {
            selectedPosition = position;
          });
        },
      ),
    );
  }
}

Я что-то пропустил?

Спасибо

< Сильный > Edited

Мой домашний таб

import 'package:flutter/material.dart';
import 'package:tokopedia/widgets/banner_belanja_untung.dart';
import 'package:tokopedia/widgets/banner_beli_kebutuhan.dart';
import 'package:tokopedia/widgets/banner_promo_special.dart';
import 'package:tokopedia/widgets/image_slider.dart';
import 'package:tokopedia/widgets/kategori_pilihan.dart';
import 'package:tokopedia/widgets/menu_item.dart';
import 'package:tokopedia/widgets/most_trending_product.dart';
import 'package:tokopedia/widgets/promo_product.dart';

class HomeTab extends StatefulWidget {
  @override
  _HomeTabState createState() => _HomeTabState();
}

class _HomeTabState extends State<HomeTab> {
  @override
  Widget build(BuildContext context) {
    var greyArea = Container(
      height: 10.0,
      color: Colors.grey[200],
    );
    return SingleChildScrollView(
      child: Column(
        children: <Widget>[
          ImageSliderWidget(),
          MenuItemWidget(),
          greyArea,
          PromoProduct(),
          greyArea,
          BannerPromoSpecial(),
          KategoriPilihan(),
          greyArea,
          BannerBelanjaUntung(),
          greyArea,
          MostTrendingProduct(),
          greyArea,
          BannerBeliKebutuhan(),
          greyArea,
          KategoriPilihan(),
        ],
      ),
    );
  }
}

Внутри моего PromoProduct виджета

import 'dart:async';

import 'package:flutter/material.dart';

class PromoProduct extends StatefulWidget {
  @override
  _PromoProductState createState() => _PromoProductState();
}

class _PromoProductState extends State<PromoProduct> {
  DateTime time = DateTime.now();

  @override
  void initState() {
    Timer(Duration(seconds: 1), () {
      setState(() {
        time = time.add(Duration(seconds: -1));
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    var promoProductItems = [
      {
        "image": "assets/images/product/tas.jpg",
        "real_price": "Rp 249.000",
        "discount_price": "Rp 87.150",
        "discount_percent": "65",
      },
      {
        "image": "assets/images/product/qtela.jpg",
        "real_price": "Rp 25.000",
        "discount_price": "Rp 20.000",
        "discount_percent": "20",
      },
      {
        "image": "assets/images/product/tropicana_slim.jpg",
        "real_price": "Rp 83.500",
        "discount_price": "Rp 58.500",
        "discount_percent": "30",
      },
      {
        "image": "assets/images/product/pipo_frixion.jpg",
        "real_price": "Rp 27.000",
        "discount_price": "Rp 16.200",
        "discount_percent": "40",
      },
      {
        "image": "assets/images/product/bioderma_sebium.jpg",
        "real_price": "Rp 252.625",
        "discount_price": "Rp 155.000",
        "discount_percent": "39",
      },
      {
        "image": "assets/images/product/maxim_new_prestige.jpg",
        "real_price": "Rp 612.000",
        "discount_price": "Rp 263.000",
        "discount_percent": "57",
      },
    ];
    return Column(
      children: <Widget>[
        Container(
          padding: EdgeInsets.all(12.0),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              Container(
                child: Row(
                  children: <Widget>[
                    Text("Flash Sale   ",
                        style: TextStyle(
                          fontSize: 16.0,
                          fontWeight: FontWeight.bold,
                        )),
                    Container(
                      padding: EdgeInsets.all(4.0),
                      decoration: BoxDecoration(
                        color: Color(0xffff3e2f),
                        borderRadius: BorderRadius.all(Radius.circular(6.0)),
                      ),
                      child: Text(
                        time.hour.toString().padLeft(2, "0"),
                        style: TextStyle(
                          color: Colors.white,
                        ),
                      ),
                    ),
                    Text(
                      " : ",
                      style: TextStyle(
                        color: Color(0xffff3e2f),
                      ),
                    ),
                    Container(
                      padding: EdgeInsets.all(4.0),
                      decoration: BoxDecoration(
                        color: Color(0xffff3e2f),
                        borderRadius: BorderRadius.all(Radius.circular(6.0)),
                      ),
                      child: Text(
                        time.minute.toString().padLeft(2, "0"),
                        style: TextStyle(
                          color: Colors.white,
                        ),
                      ),
                    ),
                    Text(
                      " : ",
                      style: TextStyle(
                        color: Color(0xffff3e2f),
                      ),
                    ),
                    Container(
                      padding: EdgeInsets.all(4.0),
                      decoration: BoxDecoration(
                        color: Color(0xffff3e2f),
                        borderRadius: BorderRadius.all(Radius.circular(6.0)),
                      ),
                      child: Text(
                        time.second.toString().padLeft(2, "0"),
                        style: TextStyle(
                          color: Colors.white,
                        ),
                      ),
                    ),
                  ],
                ),
              ),
              Text("Lihat Semuanya",
                  style: TextStyle(
                    color: Colors.green,
                  )),
            ],
          ),
        ),
        Container(
          width: MediaQuery.of(context).size.width,
          height: 280.0,
          child: IgnorePointer(
            child: GridView.count(
              crossAxisCount: 3,
              children: List.generate(
                promoProductItems.length,
                (index) {
                  return Column(
                    children: <Widget>[
                      Stack(
                        children: <Widget>[
                          Container(
                            height: 85.0,
                            child: Image.asset(
                              promoProductItems[index]["image"],
                            ),
                          ),
                          Positioned(
                            top: 0,
                            right: 0,
                            child: Container(
                              padding: EdgeInsets.all(4.0),
                              child: Text(
                                "${promoProductItems[index]["discount_percent"]} OFF",
                                style: TextStyle(
                                  color: Colors.red[900],
                                  fontSize: 10.0,
                                  fontWeight: FontWeight.bold,
                                ),
                              ),
                              decoration: BoxDecoration(
                                color: Colors.red[100],
                                border: Border.all(
                                  color: Colors.red,
                                  width: 2.0,
                                ),
                                borderRadius: BorderRadius.all(
                                  Radius.circular(12.0),
                                ),
                              ),
                            ),
                          ),
                        ],
                      ),
                      Text(
                        promoProductItems[index]["real_price"],
                        style: TextStyle(
                          decoration: TextDecoration.lineThrough,
                        ),
                      ),
                      Text(
                        promoProductItems[index]["discount_price"],
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          color: Colors.orange[900],
                        ),
                      ),
                    ],
                  );
                },
              ),
            ),
          ),
        ),
      ],
    );
  }
}
1
Bertho Joris 17 Апр 2020 в 21:39

2 ответа

Лучший ответ

Это не совсем правильный путь, но иногда вам придется его использовать. Понравился твой вопрос. Определите bool и измените его, когда виджет будет удален. И не используйте setState без него. Например;

DateTime time = DateTime.now();
bool _disposed = false;

@override
void initState() {
  Timer(Duration(seconds: 1), () {
    if (!_disposed)
      setState(() {
        time = time.add(Duration(seconds: -1));
      });
  });
  super.initState();
}

@override
void dispose() {
  _disposed = true;
  super.dispose();
}
1
malibayram91 17 Апр 2020 в 19:38

На одной из ваших вкладок вы используете метод запуска setState некоторых кодов. Вероятно, в будущем функции. Пожалуйста, поделитесь внутри вкладки, что вы получаете эту ошибку, когда вы выходите из нее.

0
malibayram91 17 Апр 2020 в 19:40