momo/lib/material/home.dart

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:momo/material/gallery.dart';

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  int selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text(
          "App Header",
          style: TextStyle(fontWeight: FontWeight.bold),
        ),
        elevation: 10,
      ),
      body: Row(
        children: [
          MediaQuery.of(context).size.width > 640
              ? NavigationRail(
                  elevation: 10,
                  backgroundColor: const Color(0xffebf6f5),
                  leading: MediaQuery.of(context).size.width >= 1008
                      ? const Text(
                          "Side Header",
                          style: TextStyle(
                              fontWeight: FontWeight.bold, fontSize: 36),
                        )
                      : null,
                  onDestinationSelected: (idx) {
                    setState(() {
                      selectedIndex = idx;
                    });
                  },
                  destinations: const [
                    NavigationRailDestination(
                        icon: Icon(Icons.photo_album), label: Text("相册")),
                    NavigationRailDestination(
                        icon: Icon(Icons.person), label: Text("用户"))
                  ],
                  extended: MediaQuery.of(context).size.width >= 1008,
                  selectedIndex: selectedIndex)
              : const SizedBox(
                  width: 0,
                ),
          Expanded(child: pageList[selectedIndex])
        ],
      ),
      bottomNavigationBar: MediaQuery.of(context).size.width <= 640
          ? BottomNavigationBar(
              elevation: 10,
              currentIndex: selectedIndex,
              onTap: (idx) {
                setState(() {
                  selectedIndex = idx;
                });
              },
              items: const [
                  BottomNavigationBarItem(
                      icon: Icon(Icons.photo_album), label: "相册"),
                  BottomNavigationBarItem(icon: Icon(Icons.person), label: "用户")
                ])
          : null,
    );
  }
}

List<Widget> pageList = [
  Gallery(),
  Scaffold(
    body: Placeholder(),
  )
];