如何在颤振中使用来自提供者的嵌套子程序进行notifyListeners？

Question

伙计们，我从“颤栗”开始，我决定做一个小游戏，比如“饼干键”来训练，但是我刚遇到了国家管理的问题.

我使用提供程序来传播"GameController“，其目的是更新播放器的资源并进行计算。

我设法在任何地方获得"GameController“，但是当我与资源(”GameController“中的对象)交互时，这个是最新的，但不在UI中，它不会改变.

main.dart：

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'controllers/GameController.dart';

void main() => runApp(MokaOnline());

class MokaOnline extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (context) => GameController()),
      ],
      child: MokaOnlineApp(),
    );
  }
}

class MokaOnlineApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'MokaOnline',
      home: Test(),
    );
  }
}

class Test extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Consumer<GameController>(
      builder: (context, gameControler, _) {
        final _mokaResource =
            gameControler.essentialResourceController.mokaResource;

        return Container(
          child: Column(
            children: <Widget>[
              Text('Moka : ${_mokaResource.getResource()}'),
              FlatButton(
                onPressed: () {
                  _mokaResource.increment();
                },
                child: Text('Add Moka'),
              )
            ],
          ),
        );
      },
    );
  }
}

GameController.dart：

import 'package:flutter/foundation.dart';
import 'package:mokaonline/controllers/EssentialResourceController.dart';

class GameController {
  EssentialResourceController _essentialResourceController =
      EssentialResourceController();

  EssentialResourceController get essentialResourceController =>
      _essentialResourceController;
}

EssentialResourceController.dart：

import 'package:mokaonline/models/essentialResources/MokaResourceModel.dart';
import 'package:mokaonline/models/essentialResources/ResourceEssentialInterface.dart';

class EssentialResourceController {
  ResourceEssentialInterface _mokaResource = MokaResourceModel();

  ResourceEssentialInterface get mokaResource => _mokaResource;
}

MokaResourceModel.dart：

import 'package:flutter/foundation.dart';
import 'package:mokaonline/models/essentialResources/ResourceEssentialInterface.dart';

class MokaResourceModel extends ChangeNotifier
    implements ResourceEssentialInterface {
  int _moka = 0;

  void increment() {
    _moka++;
    notifyListeners();
  }

  @override
  int getResource() {
    return _moka;
  }
}

我知道UI没有刷新，因为更新的不是真正的"GameController“.但我看不出如何构造否则的代码。

不管怎样，谢谢你的病人，祝你今天愉快！

Answer 1

您正在寻找类似于提供程序中的嵌套对象的东西。

就像Flutter Provider Nested Objects

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:flutter/foundation.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (context) => MokaResourceModel()),
        ChangeNotifierProxyProvider<MokaResourceModel, EssentialResourceController>(
            create: (_) => EssentialResourceController(),
            update: (_, moka, essR) => essR..mokaResourceModel=moka
        ),
        ChangeNotifierProxyProvider<EssentialResourceController, GameController>(
            create: (_) => GameController(),
            update: (_, essR, gamec) => gamec..essentialResourceController=essR
        )
      ],
      child: MokaOnlineApp(),
    );
  }
}

class MokaOnlineApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'MokaOnline',
      home: Test(),
    );
  }
}

class Test extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Consumer<GameController>(
      builder: (context, gameControler, _) {
        final _mokaResource = gameControler.essentialResourceController.mokaResourceModel;

        return new SafeArea(
          child: Container(
            child: Column(
              children: <Widget>[
                Text('Moka : ${_mokaResource.getResource()}'),
                FlatButton(
                  onPressed: () {
                    _mokaResource.increment();
                  },
                  child: Text('Add Moka'),
                )
              ],
            ),
          ),
        );
      },
    );
  }
}

class GameController extends ChangeNotifier {

  GameController() {_EssentialResourceController = EssentialResourceController();}

  EssentialResourceController _EssentialResourceController = EssentialResourceController();

  EssentialResourceController get essentialResourceController => _EssentialResourceController;

  set essentialResourceController(EssentialResourceController value)
  {
    _EssentialResourceController = value;
    notifyListeners();
  }

}

class EssentialResourceController extends ChangeNotifier {

  EssentialResourceController() {_MokaResourceModel = MokaResourceModel();}

  MokaResourceModel _MokaResourceModel = MokaResourceModel();

  MokaResourceModel get mokaResourceModel => _MokaResourceModel;

  set mokaResourceModel(MokaResourceModel value)
  {
    _MokaResourceModel = value;
    notifyListeners();
  }

}

class MokaResourceModel extends ChangeNotifier {

  int _moka = 0;

  void increment() {
    _moka++;
    notifyListeners();
  }

  @override
  int getResource() {
    return _moka;
  }
}

Answer 2

有些地方不对劲，但也许你发现了错误。

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:flutter/foundation.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (context) => MokaResourceModel()),
        ChangeNotifierProvider(create: (context) => WoodResource()),
        ChangeNotifierProxyProvider2<MokaResourceModel, WoodResource, EssentialResourceController>(
            create: (_) => EssentialResourceController(),
            update: (_, moka, wood, essR) {
                    essR..mokaResourceModel=moka;
                    essR..woodResource=wood;
                  },
        ),
        ChangeNotifierProxyProvider<EssentialResourceController, GameController>(
            create: (_) => GameController(),
            update: (_, essR, gamec) => gamec..essentialResourceController=essR
        )
      ],
      child: MokaOnlineApp(),
    );
  }
}

class MokaOnlineApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'MokaOnline',
      home: Test(),
    );
  }
}

class Test extends StatelessWidget {
  @override
  Widget build(BuildContext context) {


    return Consumer<GameController>(
      builder: (context, gameControler, _) {
        final _moka = gameControler.essentialResourceController.mokaResourceModel;
        final _wood = gameControler.essentialResourceController.woodResource;

        return new SafeArea(
          child: Container(
            child: Column(
              children: <Widget>[
                Text('Moka : ${_moka.getResource()}'),
                FlatButton(
                  onPressed: () {
                    _moka.increment();
                  },
                  child: Text('Add Moka'),
                ),
                new Container(height: 100.0,),
                Text('Wood : ${_wood.getResource()}'),
                FlatButton(
                  onPressed: () {
                    _wood.increment();
                  },
                  child: Text('Add Wood'),
                )
              ],
            ),
          ),
        );
      },
    );
  }
}

class GameController extends ChangeNotifier {

  GameController() {_EssentialResourceController = EssentialResourceController();}

  EssentialResourceController _EssentialResourceController = EssentialResourceController();

  EssentialResourceController get essentialResourceController => _EssentialResourceController;

  set essentialResourceController(EssentialResourceController value)
  {
    _EssentialResourceController = value;
    notifyListeners();
  }

}

class EssentialResourceController extends ChangeNotifier {

  EssentialResourceController() {
    _MokaResourceModel = MokaResourceModel();
    _WoodResource = WoodResource();
  }

  MokaResourceModel _MokaResourceModel = MokaResourceModel();
  MokaResourceModel get mokaResourceModel => _MokaResourceModel;

  set mokaResourceModel(MokaResourceModel value)
  {
    _MokaResourceModel = value;
    notifyListeners();
  }

  WoodResource _WoodResource = WoodResource();
  WoodResource get woodResource => _WoodResource;
  set woodResource(WoodResource value)
  {
    _WoodResource = value;
    notifyListeners();
  }

}

class MokaResourceModel extends ChangeNotifier {

  int _moka = 0;

  void increment() {
    _moka++;
    notifyListeners();
  }

  @override
  int getResource() {
    return _moka;
  }
}

class WoodResource extends ChangeNotifier {

  int _wood = 0;

  void increment() {
    _wood++;
    notifyListeners();
  }

  @override
  int getResource() {
    return _wood;
  }

}

Answer 3

这也不是真的更好

ChangeNotifierProvider(create: (context) => MokaResourceModel()),
        ChangeNotifierProvider(create: (context) => WoodResource()),
        ChangeNotifierProxyProvider<MokaResourceModel, EssentialResourceController>(
            key: UniqueKey(),
            create: (_) => EssentialResourceController(),
            update: (_, moka, essR) => essR..mokaResourceModel=moka
        ),
        ChangeNotifierProxyProvider<WoodResource, EssentialResourceController>(
          key: UniqueKey(),
            create: (_) => EssentialResourceController(),
            update: (_, wood, essR) => essR..woodResource=wood
        ),
        ChangeNotifierProxyProvider<EssentialResourceController, GameController>(
            create: (_) => GameController(),
            update: (_, essR, gamec) => gamec..essentialResourceController=essR
        )