使用Flutter Provider软件包时出现问题 [英] Problems while using Flutter Provider package

问题描述

我正在创建一个非常简单的应用来练习flutter提供程序包。该应用程序带有一个灯泡，单击时，应使用提供程序更改其背景和屏幕的背景。但这似乎不起作用。 TBH，这很令人困惑

I am creating a very simple app to practice flutter provider package. The app has a bulb which on click , should change it's background and the screen's background , using provider. But this doesnt seem to work. TBH this is a lot confusing

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

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

class Data extends ChangeNotifier{
  bool isOn = false;
  void toggle(){
    this.isOn = !this.isOn;
    notifyListeners();
    print("new value is $isOn");
  }
}

class MainApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<Data>(
      create: (context) => Data(),
      child: MaterialApp(
        home: Home(),
      ),
    );
  }
}

class Home extends StatefulWidget {
  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      backgroundColor: Provider.of<Data>(context).isOn ? Colors.yellow[100] : Colors.black,
      body: Center(
        child: Column(
          children: <Widget>[
            Stick(),
            Bulb(),
          ],
        ),
      ),
    );
  }
}

class Stick extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 150,
      width: 40,
      color: Colors.brown,
    );
  }
}

class Bulb extends StatefulWidget {
  @override
  _BulbState createState() => _BulbState();
}

class _BulbState extends State<Bulb> {
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 200,
      width: 250,
      decoration: BoxDecoration(
          borderRadius: BorderRadius.only(
              topLeft: Radius.circular(100),
              topRight: Radius.circular(100),
              bottomLeft: Radius.circular(30),
              bottomRight: Radius.circular(30)),
          color: Provider.of<Data>(context).isOn ? Colors.yellow : Colors.white,
      ),
      child: GestureDetector(
        onTap: (){
          Provider.of<Data>(context).toggle();
          setState(() {
          });
        },
      ),
    );
  }
}

树形结构有一个主应用程序，其中包含一个Home应用程序，它在容器中还包含其他2个小部件，一根棍子和一个灯泡。单击灯泡时，我尝试更新灯泡的背景和主页小部件。灯泡有手势检测器
任何提示或帮助都赞赏

The tree structure has a main app which houses a Home app , which houses 2 other widgets , a stick and a bulb inside a container. I am trying to update the background of bulb and the Home widget when the bulb is clicked. Bulb has a gesture detector Any kind of hint or help appreciated

推荐答案

尝试添加侦听：false 到提供程序调用：

Try to add listen: false to the provider call :

Provider.of<Data>(context, listen: false).toggle();

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