老师，请教个问题：
点击HomeTabPage页面的 banner 进入 VideoDetailPage页面，为什么都会调用 BottomNavigator 的 initState 方法，我认为不应该重新创建的？

在VideoDetailPage页面点击 左上角 返回icon，为什么会调用 HomePage 的 initState 方法？应该已经创建过了，不应该重新创建了

import 'package:flutter/material.dart';
import 'package:vione_bll/navigator/hi_navigator.dart';
import 'package:vione_bll/page/index/favorite_page.dart';
import 'package:vione_bll/page/index/home_page.dart';
import 'package:vione_bll/page/index/profile_page.dart';
import 'package:vione_bll/page/index/ranking_page.dart';
import 'package:vione_bll/utils/color.dart';

class BottomNavigator extends StatefulWidget {
  @override
  _BottomNavigatorState createState() => _BottomNavigatorState();
}

class _BottomNavigatorState extends State<BottomNavigator>
    with AutomaticKeepAliveClientMixin {
  final Color _defaultColor = Colors.grey;
  final Color _activeColor = primary;
  int _current = 0;
  final PageController _controller = PageController(initialPage: 0);
  List<Widget> _pages;
  bool _hasBuild = false;

  @override
  void initState() {
    super.initState();
    print("---_BottomNavigatorState---initState");
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    _pages = [HomePage(), RankingPage(), FavoritePage(), ProfilePage()];
    if (!_hasBuild) {
      HiNavigator.getInstance().onBottomTagChange(_current, _pages[_current]);
      _hasBuild = true;
    }
    return Scaffold(
      body: PageView(
        controller: _controller,
        children: _pages,
        onPageChanged: (index) {
          HiNavigator.getInstance().onBottomTagChange(index, _pages[index]);
          this.setState(() {
            this._current = index;
          });
        },
        physics: NeverScrollableScrollPhysics(),
      ),
      bottomNavigationBar: BottomNavigationBar(
        onTap: (index) {
          _controller.jumpToPage(index); //回调用PageView的onPageChanged方法
          // HiNavigator.getInstance().onJumpTo(RouteStatus.detail, args: {"videoMo": VideoMo(vid: "112")});
        },
        type: BottomNavigationBarType.fixed,
        items: [
          _bottomItem('首页', Icons.home, 0),
          _bottomItem('排行', Icons.local_fire_department, 1),
          _bottomItem('收藏', Icons.favorite, 2),
          _bottomItem('我的', Icons.live_tv, 3)
        ],
        currentIndex: _current,
        unselectedItemColor: _defaultColor,
        selectedItemColor: _activeColor,
      ),
    );
  }

  _bottomItem(String title, IconData iconData, int index) {
    return BottomNavigationBarItem(
        icon: Icon(
          iconData,
          color: _defaultColor,
        ),
        activeIcon: Icon(
          iconData,
          color: _activeColor,
        ),
        label: title);
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  bool get wantKeepAlive => true;
}

import 'package:flutter/material.dart';
import 'package:vione_bll/core/hi_state.dart';
import 'package:vione_bll/dao/home_dao.dart';
import 'package:vione_bll/http/core/hi_error.dart';
import 'package:vione_bll/modle/home_mo.dart';
import 'package:vione_bll/navigator/hi_navigator.dart';
import 'package:vione_bll/page/index/home_tab_page.dart';
import 'package:vione_bll/utils/color.dart';
import 'package:vione_bll/utils/toast.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends HiState<HomePage>
    with AutomaticKeepAliveClientMixin, TickerProviderStateMixin {
  RouteChangeListener _listener;
  TabController _controller;
  List<BannerMo> bannerList = [];
  List<CategoryMo> categoryList = [];
  @override
  void initState() {
    print("---_HomePageState -initState-----");
    super.initState();
    _controller = TabController(length: categoryList.length, vsync: this);
    // HiNavigator.getInstance().addListener(this._listener = (current, pre) {
    //   print('home:current:${current.page}');
    //   print('home:pre:${pre.page}');
    //   if (widget == current.page || current.page is HomePage) {
    //     print('打开了首页:onResume');
    //   } else if (widget == pre?.page || pre?.page is HomePage) {
    //     print('首页:onPause');
    //   }
    // });
    loadData();
  }

  @override
  void dispose() {
    HiNavigator.getInstance().removeListener(_listener);
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      body: Column(
        children: [
          Container(
            color: Colors.white,
            padding: EdgeInsets.only(top: 30),
            child: _tabBar(),
          ),
          Flexible(
            child: TabBarView(
                controller: _controller,
                children: categoryList.map((tab) {
                  return HomeTabPage(
                    name: tab.name,
                    bannerList: tab.name == '推荐' ? bannerList : null,
                  );
                }).toList()),
          ),
        ],
      ),
    );
  }

  @override
  bool get wantKeepAlive => true;

  _tabBar() {
    return TabBar(
        controller: _controller,
        isScrollable: true,
        labelColor: Colors.black,
        indicator: UnderlineTabIndicator(
          borderSide: BorderSide(color: primary, width: 3),
          insets: EdgeInsets.only(left: 20, right: 20),
        ),
        tabs: categoryList.map<Tab>(
          (tab) {
            return Tab(
              child: Padding(
                padding: EdgeInsets.only(left: 5, right: 5),
                child: Text(
                  tab.name,
                  style: TextStyle(fontSize: 16, color: Colors.black),
                ),
              ),
            );
          },
        ).toList());
  }

  void loadData() async {
    try {
      HomeMo ret = await HomeDao.get('推荐');
      if (ret.categoryList != null) {
        _controller =
            TabController(length: ret.categoryList.length, vsync: this);
      }
      this.setState(() {
        categoryList = ret.categoryList;
        bannerList = ret.bannerList;
      });
    } on NeedAuth catch (e) {
      showWarnToast(e.message);
    } on HiNetError catch (e) {
      showWarnToast(e.message);
    }
  }
}

import 'package:flutter/material.dart';
import 'package:vione_bll/modle/home_mo.dart';
import 'package:vione_bll/widget/hi_banner.dart';

class HomeTabPage extends StatefulWidget {
  final String name;
  final List<BannerMo> bannerList;

  const HomeTabPage({Key key, this.name, this.bannerList}) : super(key: key);

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

class _HomeTabPageState extends State<HomeTabPage>
    with AutomaticKeepAliveClientMixin {
  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Container(
      child: ListView(
        children: [
          if (widget.bannerList != null) _banner(),
        ],
      ),
    );
  }

  _banner() {
    return Padding(
      padding: EdgeInsets.only(left: 8, right: 8),
      child: HiBanner(widget.bannerList),
    );
  }

  @override
  bool get wantKeepAlive => true;
}

import 'package:flutter/material.dart';
import 'package:vione_bll/modle/home_mo.dart';

class VideoDetailPage extends StatefulWidget {
  final Map args;

  const VideoDetailPage({
    Key key,
    this.args,
  }) : super(key: key);

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

class _VideoDetailPageState extends State<VideoDetailPage> {
  @override
  void initState() {
    super.initState();
    print("---_VideoDetailPageState -- initState");
  }

  @override
  Widget build(BuildContext context) {
    VideoMo videoMo = widget.args['videoMo'];
    return Scaffold(
      appBar: AppBar(),
      body: Container(
        child: Text("视频详情页： vid: ${videoMo.vid}"),
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:vione_bll/dao/login_dao.dart';
import 'package:vione_bll/db/hi_cache.dart';
import 'package:vione_bll/navigator/bottom_navigator.dart';
import 'package:vione_bll/navigator/hi_navigator.dart';
import 'package:vione_bll/page/launcher/login_page.dart';
import 'package:vione_bll/page/launcher/registration_page.dart';
import 'package:vione_bll/page/video_detail_page.dart';
import 'package:vione_bll/utils/color.dart';
import 'package:vione_bll/utils/toast.dart';

void main() {
  runApp(BiliApp());
}

class BiliApp extends StatefulWidget {
  @override
  _BiliAppState createState() => _BiliAppState();
}

class _BiliAppState extends State<BiliApp> {
  BiliRouterDelegate _routerDelegate = BiliRouterDelegate();

  @override
  Widget build(BuildContext context) {
    print("BiliApp -- build");

    return FutureBuilder<HiCache>(
      //进行初始化
      future: HiCache.preInit(),
      builder: (BuildContext context, AsyncSnapshot<HiCache> snapshot) {
        //定义路由
        var widget = snapshot.connectionState == ConnectionState.done
            ? Router(
                routerDelegate: _routerDelegate,
              )
            : Scaffold(
                body: Center(
                  child: CircularProgressIndicator(),
                ),
              );
        return MaterialApp(
          home: widget,
          theme: ThemeData(
            primarySwatch: white,
          ),
        );
      },
    );
  }
}

class BiliRouterDelegate extends RouterDelegate<BiliRoutePath>
    with ChangeNotifier, PopNavigatorRouterDelegateMixin<BiliRoutePath> {
  //为Navigator设置一个key，必要的时候可以通过navigatorKey.currentState来获取到NavigatorState对象
  @override
  GlobalKey<NavigatorState> get navigatorKey => GlobalKey();

  BiliRouterDelegate() {
    HiNavigator.getInstance().registerRouteJump(
        RouteJumpListener((RouteStatus routeStatus, {Map args}) {
      _routeStatus = routeStatus;
      this.args = args;
      notifyListeners();
    }));
  }

  List<MaterialPage> pages = [];
  RouteStatus _routeStatus = RouteStatus.home;
  Map args;

  RouteStatus get routeStatus {
    if (_routeStatus != RouteStatus.registration && !hasLogin) {
      _routeStatus = RouteStatus.login;
    }
    return _routeStatus;
  }

  bool get hasLogin => LoginDao.getBoardingPass() != null;

  @override
  Widget build(BuildContext context) {
    print("BiliRouterDelegate -- build");
    int index = getPageIndex(pages, routeStatus);
    List<MaterialPage> tempPages = pages;
    if (index != -1) {
      ///要打开的页面在栈中已存在，则将该页面和它上面的所有页面都出栈
      ///tips 具体规则可以根据需要进行调整，这里要求栈中只允许有一个同样的页面的实例
      tempPages = tempPages.sublist(0, index);
    }
    var page;
    if (routeStatus == RouteStatus.home) {
      //跳转首页时，将栈中其它页面进行出栈，因为首页不可回退
      pages.clear();
      page = pageWrap(
        BottomNavigator(),
      );
    } else if (routeStatus == RouteStatus.detail) {
      page = pageWrap(VideoDetailPage(args: args));
    } else if (routeStatus == RouteStatus.registration) {
      page = pageWrap(RegistrationPage());
    } else if (routeStatus == RouteStatus.login) {
      page = pageWrap(LoginPage());
    }
    //重建一个数组，否则pages因引用没有改变路由不会生效
    tempPages = [...tempPages, page];
    //通知路由信息变化
    HiNavigator.getInstance().notify(tempPages, pages);
    pages = tempPages;
    return WillPopScope(
      child: Navigator(
        key: navigatorKey,
        pages: pages,
        onPopPage: (route, result) {
          if (route.settings is MaterialPage) {
            //登录页未登录，返回拦截
            if ((route.settings as MaterialPage).child is LoginPage) {
              if (!hasLogin) {
                showWarnToast("请先登录");
                return false;
              }
            }
          }
          //执行返回操作
          if (!route.didPop(result)) {
            return false;
          }
          var tempPages = [...pages];
          //进行出栈
          pages.removeLast();
          //通知路由信息变化
          HiNavigator.getInstance().notify(pages, tempPages);
          return true;
        },
      ),
      onWillPop: () async => !await navigatorKey.currentState.maybePop(),
    );
  }

  @override
  void addListener(listener) {
    print("BiliRouterDelegate -- addListener");
    super.addListener(listener);
  }

  @override
  Future<bool> popRoute() {
    print("BiliRouterDelegate -- popRoute");
    return super.popRoute();
  }

  @override
  void dispose() {
    print("BiliRouterDelegate -- dispose");
    super.dispose();
  }

  @override
  Future<void> setNewRoutePath(BiliRoutePath configuration) async {
    print("BiliRouterDelegate -- setNewRoutePath");
  }
}

class BiliRoutePath {
  final String location;
  BiliRoutePath.home() : location = "/";
  BiliRoutePath.detail() : location = "/detail";
}