在Flutter中的平板电脑上制作固定的应用程序级菜单，而不是在抽屉上 [英] Making fixed app-wide menu instead of Drawer on tablets in Flutter

问题描述

我的应用程序有很多路线，几乎每条路线都使用具有相同Drawer菜单的Scaffold在应用程序内部导航(我自己的CustomDrawer小部件).对于具有大屏幕的设备，我希望始终在布局的左侧显示菜单，而不要使用抽屉"(在Gmail应用中，它的工作方式与此相同.我附上了图片).换句话说，我需要使用固定菜单进行响应式布局.

My application has a lot of routes and almost every route uses Scaffold with the same Drawer menu to navigate inside the app (my own CustomDrawer widget). As for devices with big screen, I want to always show the menu on the left side in layout, instead of using Drawer (it works like this in Gmail app. I attached a pic). In other words, I need to make a responsive layout with fixed menu.

我尝试过的事情:

• 我知道您可以使用LayoutBuilder来学习约束大小；
• 在每条路径内进行相同的布局都可以，但是这是一个不好的解决方案，因为每条路径都会为自己建立菜单(滚动位置会有所不同，许多菜单会有许多状态，等等).我需要一个适用于整个不同路线的应用程序级菜单，但无法在顶部路线上进行布局；
• 将所有路由压缩为一条路由，同时更改主要内容的状态将需要大量的重构，而且听起来一点也不好.

在React中，应用布局看起来像这样:

In React the app layout would look something like this:

    <App>
      <Menu />
      <main className="content">
        <Switch>
          <Route path="/about" component={About} />
          <Route path="/contact" component={Contact} />
          <Route path="/" component={Home} />
        </Switch>
      </main>
    </App>

但是我不知道如何在Flutter中制作这样的东西.

But I have no idea how to make something like this in Flutter.

tl; dr:要使UI对大屏幕响应，我想显示固定菜单而不是抽屉.一个菜单可用于整个应用程序，而不是每个路线.

tl;dr: To make UI responsive for big screens, I want to show fixed menu instead of Drawer. One menu for whole app, not for every route.

推荐答案

诀窍是使用嵌套的导航器.如果视口的宽度很大，则将菜单与内容放在一起，否则将菜单作为 drawer 参数传递给 Scaffold .

The trick was to use a nested navigator. If viewport's width is big, I put a menu in a row with content, otherwise pass a menu to Scaffold as drawer parameter.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  MyHomePage({Key key, this.title}) : super(key: key);

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

class _MyHomePageState extends State<MyHomePage> {
  final routes = List.generate(20, (i) => 'test $i');

  final navigatorKey = GlobalKey<NavigatorState>();

  bool isMenuFixed(BuildContext context) {
    return MediaQuery.of(context).size.width > 500;
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    final menu = Container(
      color: theme.canvasColor,
      child: SafeArea(
        right: false,
        child: Drawer(
          elevation: 0,
          child: ListView(
            children: <Widget>[
              for (final s in routes)
                ListTile(
                  title: Text(s),
                  onTap: () {
                    // Using navigator key, because the widget is above nested navigator  
                    navigatorKey.currentState.pushNamedAndRemoveUntil(s, (r) => false);

                    // navigatorKey.currentState.pushNamed(s);
                  },
                ),
            ],
          ),
        )
      )
    );

    return Row(
      children: <Widget>[
        if (isMenuFixed(context))
          menu,
        Expanded(
          child: Navigator(
            key: navigatorKey,
            initialRoute: '/',
            onGenerateRoute: (settings) {
              return MaterialPageRoute(
                builder: (context) {
                  return Scaffold(
                    appBar: AppBar(
                      title: Text(settings.name),
                    ),
                    body: SafeArea(
                      child: Text(settings.name),
                    ),
                    drawer: isMenuFixed(context) ? null : menu,
                  );
                },
                settings: settings
              );
            },
          ),
        ),
      ],
    );
  }
}

这篇关于在Flutter中的平板电脑上制作固定的应用程序级菜单，而不是在抽屉上的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！