Flutter Listview 为什么标题没有改变？

Question

所以我有一个问题：我的问题有点复杂，但我试着向你解释一下...... 所以我的应用程序就像这样，当我点击图像时，图像会改变，标题也会改变（比如粥）您可以点击标题进入第二页，但标题没有改变这是我的问题，因为我正在使用列表

这里是 chnaging（第一个截图）：

class DicePage extends StatefulWidget {
  const DicePage({Key? key}) : super(key: key);

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

class _DicePageState extends State<DicePage> {
  int PicNumber = 1;

  void changeDiceNumber() {
    setState(() {
      PicNumber = Random().nextInt(4) +1;
    });
  }



  final List<Sachen> infoBank = [
    Sachen(title: "Schoko-Bowl", image: Image.asset("Images/frue1.png"), text: '-Mehl'),
    Sachen(title: "Smoothie-Bowl", image: Image.asset("images/frue2.png"), text: '-Zucker'),
    Sachen(title: "Porridge", image: Image.asset("images/frue3.png"), text: '-Milch'),
    Sachen(title: "Porridge", image: Image.asset("images/frue4.png"), text: '-Eier'),
    Sachen(title: "Schoko Mousse", image: Image.asset("images/frue5.png"),text: '-Butter'),

  ];


  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        children: [
          Card(
            margin: const EdgeInsets.fromLTRB(50, 35, 50, 0),
            elevation: 15,
            color: const Color(0xFF4caf50),
            child: SizedBox(
              height: 80,
              width: 180,
              child: Center(
                child: Padding(
                  padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 18),
                  child: GestureDetector(
                    onTap: () {
                      Navigator.of(context).push(
                        MaterialPageRoute(
                          builder: (context) => Rezept('Dein Frühstück'),
                        ),
                      );
                    },
                      child: Center(
                          child: Text(infoBank[PicNumber].title,
                          style: const TextStyle(
                              fontSize: 20,
                            fontWeight: FontWeight.bold,
                            color: Colors.white,
                          ),
                            ),
                      ),
                  ),
                ),
              ),
            ),
          ),
          Row(
            children: [
              Expanded(
                child: TextButton(
                  onPressed: () {
                    setState(() {
                      PicNumber++;
                    });
                    changeDiceNumber();
                    print('LeftDiceNumber = $PicNumber');
                  },
                  child: Container(
                    height: 415,
                    width: 350,
                    margin: const EdgeInsets.fromLTRB(10, 20, 10, 20),
                    decoration: BoxDecoration(
                      border: Border.all(
                        width: 3,
                        color: Colors.grey.shade700,
                      ),
                    ),
                    child: FittedBox(
                        child: infoBank[PicNumber].image,
                    fit: BoxFit.fill,
                      clipBehavior: Clip.hardEdge,
                    ),
                  ),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

这里没改，是第二张截图的代码：


import 'package:flutter/material.dart';
import 'Sachen.dart';
import 'dart:math';


class Rezept extends StatelessWidget{
  final String rezept;
  Rezept(this.rezept);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: const Color(0xFF4caf50),
        title: Text(rezept),
        foregroundColor: Colors.white,
        titleTextStyle: const TextStyle(
          fontWeight: FontWeight.bold,
          fontSize: 20,
        ),
      ),
      body: RezeptPage(),
    );
  }
}

class RezeptPage extends StatefulWidget {
  const RezeptPage ({Key? key}) : super(key: key);

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

class _RezeptPageState extends State<RezeptPage> {
  int PiNumber = 1;

  void changeDiceNumber() {
    setState(() {
      PiNumber = Random().nextInt(4) +1;
    });
  }



  final List<Sachen> infoBank = [
  Sachen(title: "Schoko-Bowl", image: Image.asset("Images/frue1.png"), text: '-Mehl'),
  Sachen(title: "Smoothie-Bowl", image: Image.asset("images/frue2.png"), text: '-Zucker'),
  Sachen(title: "Porridge", image: Image.asset("images/frue3.png"), text: '-Milch'),
  Sachen(title: "Porridge", image: Image.asset("images/frue4.png"), text: '-Eier'),
  Sachen(title: "Schoko Mousse", image: Image.asset("images/frue5.png"),text: '-Butter'),

];


  @override
  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        SizedBox(
          child: Padding(
            padding: EdgeInsets.fromLTRB(10, 15, 10, 15),
            child: Card(
              elevation: 8,
              child: ListTile(
                title: Center(
                    child: Text(infoBank[PiNumber].title,
                    style: const TextStyle(
                      fontSize: 20.0,
                      fontWeight: FontWeight.bold,
                    ),
                    ),
                ),
              ),
            ),
          ),
        ),
        SizedBox(
          width: 350,
          height: 500,
          child: Card(
            elevation: 5,
            margin: EdgeInsets.fromLTRB(10, 5, 10, 20),
            child: Padding(
              padding: EdgeInsets.fromLTRB(15, 15, 10, 0),
              child: RichText(text: const TextSpan(
                  text: 'Zutaten:',
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      color: Colors.black,
                      fontSize: 22.0,
                      decoration: TextDecoration.underline,
                      decorationThickness: 2.0,
                    ),
                    children: <TextSpan>[
                      TextSpan(
                          text: '\n\n-Mehl' '\n-Zucker' '\n-Milch' '\n-Eier' '\n-Butter',
                        style: TextStyle(
                          fontSize: 18,
                          fontWeight: FontWeight.normal,
                          decoration: TextDecoration.none,
                        ),
                      ),
                      TextSpan(
                        text: '\n\nZubereitung:',
                      ),
                      TextSpan(
                        text: '\n\n-Zuerst vermischen wir alles' '\n-Anschließend wird es in der Pfanne angebraten' '\n-Zuletzt mit Schokolade bestreichen und genießen',
                        style: TextStyle(
                          fontSize: 18,
                          fontWeight: FontWeight.normal,
                          decoration: TextDecoration.none,
                        ),
                      ),
                    ],
              ),
              ),
            ),
          ),
        ),
    ],
    );
}
}

我希望你理解我的问题并且已经谢谢你

Answer 1

您真正的问题是，如何将值（在您的情况下为 PiNumber）从一个屏幕传递到另一个屏幕。这就是你在推送到另一个屏幕时需要做的。这是一篇解释其工作原理的文章：https://fluttercorner.com/how-to-pass-value-from-one-screen-to-another-screen-using-navigator-in-flutter/

Flutter Listview 为什么标题没有改变？

Flutter Listview why is the title not changing?

flutter

listview

dynamic