dart - 所有屏幕都需要一个持久/相同的底部导航栏 - Flutter

Question

我是 flutter 和 Dart 的初学者。我一直在尝试在我的应用程序的三个不同页面上实现 navigationBar。切换适用于单个页面，但我在所有页面上保持事件和非事件选项卡状态时遇到问题。似乎当它导航到另一个页面时，我也失去了标签的事件状态。这是我的代码。

AppFooter.dart

import 'package:flutter/material.dart';

class AppFooter extends StatefulWidget {
  @override
  _AppFooterState createState() => _AppFooterState();
}

class _AppFooterState extends State<AppFooter> {
  int index = 0;
  @override
  Widget build(BuildContext context) {
    return new Theme(
      data: Theme.of(context).copyWith(
          // sets the background color of the `BottomNavigationBar`
          canvasColor: Colors.white,
          // sets the active color of the `BottomNavigationBar` if `Brightness` is light
          primaryColor: Colors.green,
          textTheme: Theme.of(context)
              .textTheme
              .copyWith(caption: new TextStyle(color: Colors.grey))),
      child: new BottomNavigationBar(
          type: BottomNavigationBarType.fixed,
          currentIndex: index,
          onTap: (int index) {
            setState(() {
              this.index = index;
            });
          switch (index){
            case 0:  Navigator.of(context).pushNamed('/dashboard');
            break;
            case 1:  Navigator.of(context).pushNamed('/medical centre');
            break;
            case 2:  Navigator.of(context).pushNamed('/history');
            break;

          }

          },
          items: [
            new BottomNavigationBarItem(
                backgroundColor: Colors.white,
                icon: index==0?new Image.asset('assets/images/dashboard_active.png'):new Image.asset('assets/images/dashboard_inactive.png'),
                title: new Text('Dashboard', style: new TextStyle(fontSize: 12.0))),
           new BottomNavigationBarItem(
               backgroundColor: Colors.white,
               icon: index==1?new Image.asset('assets/images/medical_sevice_active.png'):new Image.asset('assets/images/medical_sevice_inactive.png'),
               title: new Text('Health Services', style: new TextStyle(fontSize: 12.0))),
            new BottomNavigationBarItem(
                icon: InkWell(
                  child: Icon(
                    Icons.format_align_left,
                   // color: green,
                    size: 20.0,
                  ),
                ),
                title: new Text('History', style: new TextStyle(fontSize: 12.0))),
          ]),
    );
  }
}

Answer 1

如果我正确理解您的问题，您需要将底部导航栏保留在所有三个页面上。关于如何实现它，有一篇写得很好的文章。您可以在此处找到详细信息。

https://medium.com/coding-with-flutter/flutter-case-study-multiple-navigators-with-bottomnavigationbar-90eb6caa6dbf

https://github.com/bizz84/nested-navigation-demo-flutter

所有学分归原作者所有。