Json 如何提高我的应用程序在Flatter中的性能

我正在构建一个名为LiveTv的应用程序，它是一个根据不同兴趣推荐视频的应用程序。我编写的代码造成了严重的延迟，并且随着我在这个应用程序中的操作越来越多，它几乎无法运行。我已经在这个链接中包含了相同的视频

我所做的是使调用异步，并且我使用了一个三元运算符，在它下面显示了一个循环进度指示器。但是它似乎只起作用

我已经包括了由底部导航栏控制的代码。它的服务部分不包括在内，因为它的功能只是加载数据或对象，但我将包括一个或两个，以便您理解，我不想让这个问题太长

class LiveTvHomePage extends StatefulWidget {
  final String title;

  LiveTvHomePage({
    this.title,
  });

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

class _LiveTvHomePageState extends State<LiveTvHomePage> {
//GlobalKey<ScaffoldState> _drawerKey = GlobalKey<ScaffoldState>();
 

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    handleScroll(); // function which is responsible for updating the isScrollingDown variable whenever the user scrolls down
    _services();
    setState(() {
      _isLoading = false;
    });
  }

  _loadingImage() {
    return CircularProgressIndicator();
  }

  _services() {
    Services.loadDataForMovieId().then((movieIdList) {
      setState(() {
        _homeBannerObjectMovieIdList = movieIdList;
      });
    });

    Services.loadDataForMovieIdofPopularMovieSection().then((movieIdList) {
      setState(() {
        _popularMoviesMovieId = movieIdList;
      });
    });
    Services.loadDataForPopularTvShowSection().then((homePageSeriesPosterList) {
      setState(() {
        _seriesData = homePageSeriesPosterList;
      });
    });

    Services.loadDataForMusicSection().then((musicList) {
      setState(() {
        _musicCategories = musicList;
      });
    });

    Services.loadDataForPlaylistTitle().then((title) {
      setState(() {
        _musicPlaylistThemeName = title;
      });
    });

    Services.loadDataForPopularNewsChannelsNames().then((nameList) {
      setState(() {
        _popularNewsChannelNames = nameList;
      });
    });

    Services.loadDataForPopularNewsChannelsProfilePicUrls().then((urllist) {
      setState(() {
        _popularNewsChannelProfilePicUrl = urllist;
      });
    });
    Services.loadDataForLiveNewsChannelsProfilePicUrls().then((urllist) {
      setState(() {
        _liveNewsChannelProfilePicUrl = urllist;
      });
    });
    Services.loadDataForLiveNewsChannelsNames().then((nameList) {
      setState(() {
        _liveNewsChannelNames = nameList;
      });
    });
    Services.loadDataForPicOfLatestNews().then((nameList) {
      setState(() {
        _latestNewsProfilePics = nameList;
      });
    });
    Services.loadDataForOfLatestNewsTitle().then((nameList) {
      setState(() {
        _latestNewsNewsTitle = nameList;
      });
    });
    Services.loadDataForOfLatestNewsDescription().then((nameList) {
      setState(() {
        _latestNewsDescription = nameList;
      });
    });
  }

  _buildBody(var boxHeight, List<String> youtubeIdUrls) {
    return Column(
      children: <Widget>[
        Stack(
          children: <Widget>[
            _buildPageView(boxHeight, youtubeIdUrls),
            _buildCircleIndicator(youtubeIdUrls),
          ],
        ),
      ],
    );
  }

  _buildPageView(var boxHeight, List<String> youtubeIdUrls) {
    return Container(
      color: Colors.black87,
      height: boxHeight,
      child: PageView.builder(
          itemCount: 8,
          controller: _pageController,
          itemBuilder: (BuildContext context, int index) {
            try {
              // HomeBanner homeBanner=_homeBannelList[index];
              return FadeInImage.assetNetwork(
                image:
                    'https://img.youtube.com/vi/${youtubeIdUrls[index].substring(8)}/0.jpg',
                placeholder: 'assets/loading.gif',
                fit: BoxFit.fill,
              );
            } catch (e) {
              return CircularProgressIndicator();
            }
            //before return Image.network('https://img.youtube.com/vi/${videoIdOfUrlList[index]}/0.jpg',fit: BoxFit.fill,);
          },
          onPageChanged: (int index) {
            _currentPageNotifier.value = index;
          }),
    );
  }

  _buildCircleIndicator(List<String> youtubeIdUrls) {
    return Positioned(
      left: 0.0,
      right: 0.0,
      bottom: 0.0,
      child: Padding(
        padding: const EdgeInsets.all(8.0),
        child: CirclePageIndicator(
          itemCount: 8,
          currentPageNotifier: _currentPageNotifier,
        ),
      ),
    );
  }

  Widget imageDisplayed(String picUrl) {
    return Row(
      children: <Widget>[
        const SizedBox(
          width: 10,
        ),
        CircleAvatar(
          backgroundImage: NetworkImage(picUrl),
          radius: MediaQuery.of(context).size.height * 0.08,
          backgroundColor: Colors.black,
        ),
        const SizedBox(
          width: 10,
        ),
      ],
    );
  }

  Widget HorizontalListViewWitCircularCards(
      String title, List<String> urlList, List<String> nameList) {
    return Container(
      color: Colors.black,
      height: MediaQuery.of(context).size.height * 0.32,
      width: MediaQuery.of(context).size.width,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Container(
            height: MediaQuery.of(context).size.height * 0.07,
            color: Colors.black,
            alignment: Alignment.centerLeft,
            child: Padding(
              padding: const EdgeInsets.fromLTRB(10, 0, 0, 0),
              child: Text(
                title,
                style: TextStyle(fontSize: 16, color: Colors.white),
              ),
            ),
          ),
          Container(
            height: MediaQuery.of(context).size.height * 0.23,
            child: ListView.builder(
              shrinkWrap: true,
              scrollDirection: Axis.horizontal,
              itemCount: _popularNewsChannelNames.length,
              itemBuilder: (BuildContext context, int index) => Card(
                color: Colors.black,
                child: Padding(
                  padding: const EdgeInsets.symmetric(),
                  child: Column(
                    children: <Widget>[
                      imageDisplayed(urlList[index]),
                      const SizedBox(
                        height: 13,
                      ),
                      Text(
                        nameList[index],
                        style: TextStyle(color: Colors.white),
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget HorizontalGridViewOfCardsofGradientColor(int count, List<String> lst) {
    return Container(
      color: Colors.black,
      height: MediaQuery.of(context).size.height * 0.125 * count,
      child: GridView.count(
        scrollDirection: Axis.horizontal,
        crossAxisCount: count,
        shrinkWrap: true,
        mainAxisSpacing: 10,
        crossAxisSpacing: 10,
        children: List.generate(20, (index) {
          return Container(
            decoration: BoxDecoration(
              border: Border.all(
                color: Colors.black,
              ),
              borderRadius: BorderRadius.all(Radius.circular(15)),
              gradient: LinearGradient(colors: colorsForCardinMusicPage[index]),
            ),
            child: Center(
              child: Text(
                lst[index],
              ),
            ),
          );
        }),
      ),
    );
  }

  Widget HorizontalGridViewOfCardsofGradientColorWithtitle(
      int count, String title) {
    return Column(
      
    );
  }



  Widget HorizontalListViewOfButtons(List moviesPageButtonNames) {
    return Container(
      color: Colors.black,
      height: MediaQuery.of(context).size.height * 0.13,
      child: ListView.builder(
        shrinkWrap: true,
        scrollDirection: Axis.horizontal,
        itemCount: moviesPageButtonNames.length,
        itemBuilder: (BuildContext context, int index) => Row(
          children: <Widget>[
            SizedBox(
              width: 7,
            ),
            FlatButton(
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(18.0),
                  side: BorderSide(color: Colors.grey)),
              color: Colors.grey[800],
              textColor: Colors.white,
              onPressed: () {},
              child: Text(moviesPageButtonNames[index]),
            ),
            SizedBox(
              width: 10,
            )
          ],
        ),
      ),
    );
  }


  Widget NewsPageOfBottomNavigator() {
    ServicesForNewsPage.loadObjectList().then((newsPageObject) {
      _newsPage = newsPageObject;
    });
    for (var obj in _newsPage.liveChannels) {
      _newsPageLiveNewsUrls.add(obj.publisherProfilePic);
      _newsPageChannelName.add(obj.publisherName);
    }
//    print("_newsPageLiveNewsUrls");
//    print(_newsPageLiveNewsUrls);
//    print("_newsPageLiveNewsNames");
//    print(_newsPageChannelName);`
    for (var obj in _newsPage.news) {
      _newsPagePopularNewsChannelUrls.add(obj.publishers.profilePicUrl);
      _newsPagePopularNewsChannelNames.add(obj.publishers.fullName);
    }
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        HorizontalListViewWithoutViewAllForLiveNewsChannels(
            "Watch Live", _newsPageLiveNewsUrls, _newsPageChannelName),
        HorizontalListViewWitCircularCards("Popular News Channel",
            _newsPagePopularNewsChannelUrls, _newsPagePopularNewsChannelNames),
        VerticalListView(_newsPagePopularNewsChannelNames, true),
      ],
    );
  }

  Widget LifeStylePageOfBottomNavigator() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        HorizontalListViewWitCircularCards(
            "Popular Lifestyle channels", [""], [""]),
        VerticalListView(["ssss"], false),
      ],
    );
  }

  Widget SportsPageOfBottomNavigator() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        HorizontalListViewWitCircularCards(
            "Popular Sports channels", [""], [""]),
        VerticalListView(["ssss"], false),
      ],
    );
  }

  Widget returnToTopButton() {
    return Visibility(
      visible: _showButton,
      child: FlatButton(
        child: Row(
          children: <Widget>[
            Padding(
              padding: const EdgeInsets.fromLTRB(0, 7, 0, 0),
              child: Text(
                "^",
                style: TextStyle(color: Colors.white, fontSize: 27),
              ),
            ),
            Text(
              "     Return to top",
              style: TextStyle(color: Colors.white),
            ),
          ],
        ),
        onPressed: () {
          _scrollController.animateTo(0,
              duration: Duration(milliseconds: 500), curve: Curves.easeInOut);
        },
        color: Colors.red,
      ),
    );
  }

  void showFloationButton() {
    setState(() {
      _showButton = true;
    });
  }

  void hideFloationButton() {
    setState(() {
      _showButton = false;
    });
  }

  void handleScroll() async {
    // or something else..

    _scrollController.addListener(() {
      double currentScroll = _scrollController.position.pixels;
      double delta = MediaQuery.of(context).size.height;
//      print("Current scroll position is ..........$currentScroll");
//      print("delta pixel is ..........$delta");

      if (currentScroll >= delta) {
        showFloationButton();
      } else if (currentScroll <= delta) {
        hideFloationButton();
      }
    });
  }

  @override
  void dispose() {
    // TODO: implement dispose
    _scrollController.removeListener(() {});
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    List<Widget> wdgs_option = [
      HomePageForBottomNavigator(),
      MoviesPageForBottomNavigator(),
      TvSHowsPageOfBottomNavigator(),
      MusicPageofBottomNavigator(),
      // NewsPageOfBottomNavigator(), //dummy for now
      NewsPageOfBottomNavigator(),
      LifeStylePageOfBottomNavigator(),
      SportsPageOfBottomNavigator()
    ];
    return _isLoading
        ? _loadingImage()
        : Scaffold(
            //   key: _drawerKey,
            appBar: AppBar(
              automaticallyImplyLeading: false,
              leading: Icon(
                Icons.live_tv,
                color: Colors.amber,
              ),
              backgroundColor: Colors.black,
              title: Text(
                widget.title,
                style: TextStyle(fontSize: 17, color: Colors.amber),
              ),
              actions: <Widget>[
                IconButton(
                  tooltip: 'Search',
                  icon: const Icon(Icons.search),
                  onPressed: () {},
                ),
                IconButton(
                  icon: Icon(
                    MaterialCommunityIcons.xbox_controller_menu,
                    color: Colors.white,
                  ),
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(builder: (context) => DrawerWidget()),
                    );
                  },
                )
              ],
            ),
            body: SafeArea(
              child: SingleChildScrollView(
                controller: _scrollController,
                child: wdgs_option.elementAt(_selectedIndex),
              ),
            ),
            drawer: Drawer(),
            bottomNavigationBar: BottomNavigationBar(
              backgroundColor: Colors.black,
              showUnselectedLabels: true,
              type: BottomNavigationBarType.shifting,
              currentIndex: _selectedIndex,
              fixedColor: Colors.amber,
              onTap: _onItemTapped,
              items: const <BottomNavigationBarItem>[
//          Icon(
//            FontAwesome.facebook_square,
//            color: Colors.amber,
//          ),
                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(Icons.home),
                  title: Text('Home'),
                ),
                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(
                    MaterialCommunityIcons.video_vintage,
                  ),
                  title: Text(
                    'Movies',
                  ),
                ),
                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(Icons.live_tv),
                  title: Text(
                    'Tv shows',
                  ),
                ),

                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(Icons.music_video),
                  title: Text(
                    'Music',
                  ),
                ),
//          BottomNavigationBarItem(
//            backgroundColor: Colors.black,
//            icon: Icon(Icons.dehaze),
//            title: Text(
//              'More',
//            ),
//          ),

                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(Icons.radio),
                  title: Text(
                    'News',
                  ),
                ),
                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(
                    FontAwesome.heartbeat,
                  ),
                  title: Text(
                    'LifeStyle',
                  ),
                ),
                BottomNavigationBarItem(
                  backgroundColor: Colors.black,
                  icon: Icon(
                    Ionicons.md_football,
                  ),
                  title: Text(
                    'Sports',
                  ),
                ),
              ],
            ),
          );
  }
}

class LiveTvHomePage扩展StatefulWidget{
最后的字符串标题；
直播电视主页({
这个名字，
});
@凌驾
_LiveTvHomePageState createState（）=>\u LiveTvHomePageState（）；
}
类_LiveTvHomePageState扩展状态{
//GlobalKey _drawerKey=GlobalKey（）；
@凌驾
void initState（）{
//TODO:实现initState
super.initState（）；
handleScroll（）；//函数，该函数负责在用户向下滚动时更新isScrollingDown变量
_服务（）；
设置状态（）{
_isLoading=false；
});
}
_加载图像（）{
返回循环ProgressIndicator（）；
}
_服务（）{
Services.loadDataForMovieId（）.then（（movieIdList）{
设置状态（）{
_homeBannerObjectMovieIdList=电影IDList；
});
});
Services.loadDataFormoviedOfPopularMovieSection（）.then（（movieIdList）{
设置状态（）{
_popularMoviesMovieId=电影列表；
});
});
Services.loadDataForPopularTvShowSection（）.then（（homePageSeriesPosterList）{
设置状态（）{
_seriesData=主页SeriesPosterList；
});
});
Services.loadDataForMusicSection（）.then（（musicList）{
设置状态（）{
_musicCategories=musicList；
});
});
Services.loadDataForPlayTitle（）。然后（（标题）{
设置状态（）{
_MusicLayListTheMeName=标题；
});
});
Services.LoadDataForPopularNewChannelsNames（）。然后（（名称列表）{
设置状态（）{
_PopularNewChannelNames=名称列表；
});
});
Services.loadDataForPopularNewChannelsProfilePicUrls（）。然后（（URL列表）{
设置状态（）{
_PopularNewChannelProfilePicUrl=urllist；
});
});
Services.loadDataForLiveNewsChannelsProfilePicUrls（）。然后（（urllist）{
设置状态（）{
_liveNewsChannelProfilePicUrl=urllist；
});
});
Services.loadDataForLiveNewsChannelsNames（）。然后（（名称列表）{
设置状态（）{
_liveNewsChannelNames=名称列表；
});
});
Services.loadDataForPicOfLatestNews（）。然后（（名称列表）{
设置状态（）{
_latestNewsProfilePics=名称列表；
});
});
Services.loadDataForOfLatestNewsTitle（）。然后（（名称列表）{
设置状态（）{
_LatestNewsTitle=名称列表；
});
});
Services.loadDataForOfLatestNewsDescription（）。然后（（名称列表）{
设置状态（）{
_latestNewsDescription=名称列表；
});
});
}
_buildBody（变量boxHeight，列表youtubeIdUrls）{
返回列(
儿童：[
堆叠(
儿童：[
_buildPageView（框高、youtubeIdUrls），
_buildCircleIndicator（youtubeIdUrls），
],
),
],
);
}
_buildPageView（变量boxHeight，列表youtubeIdUrls）{
返回容器(
颜色：颜色。黑色87，
高度：箱高，
子项：PageView.builder(
物品计数：8，
控制器：_pageController，
itemBuilder:（构建上下文，int索引）{
试一试{
//HomeBanner HomeBanner=_homeBannelList[索引]；
返回FadeInImage.assetNetwork(
图片：
'https://img.youtube.com/vi/${youtubeIdUrls[index].子字符串（8）}/0.jpg'，
占位符：“assets/loading.gif”，
fit:BoxFit.fill，
);
}捕获（e）{
返回循环ProgressIndicator（）；
}
//返回Image.network之前（'https://img.youtube.com/vi/${videoIdOfUrlList[index]}/0.jpg'，fit:BoxFit.fill，）；
},
onPageChanged:（int索引）{
_currentPageNotifier.value=索引；
}),
);
}
_buildCircleIndicator（列出YouTubedURL）{
返回定位(
左：0.0，
右：0.0，
底部：0.0，
孩子：填充(
填充：常数边集全部（8.0），
子：CirclePageIndicator(
物品计数：8，
currentPageNotifier:\u currentPageNotifier，
),
),
);
}
显示的小部件图像（字符串picUrl）{
返回行(
儿童：[
常量大小框(
宽度：10，
),
圆形(
背景图片：NetworkImage（picUrl），
半径：MediaQuery.of（上下文）.size.height*0.08，
背景颜色：Colors.black，
),
常量大小框(
宽度：10，
),
],
);
}
Widget horizontallListViewWithCircularCards(
字符串标题、列表URL列表、列表名称列表）{
返回容器(
颜色：颜色，黑色，
高度：MediaQuery.of（context）.size.height*0.32，
宽度：MediaQuery.of（context）.size.width，
子：列(
crossAxisAlignment:crossAxisAlignment.start，
儿童：[
容器(
高度：MediaQuery.of（上下文）.size.height*0.07，
颜色：颜色，黑色，
对齐：alignment.centerLeft，
孩子：填充(
padding:const EdgeInsets.fromLTRB（10,0,0,0），
子：文本(
标题
样式：TextStyle（字体大小：16，颜色：Colors.white），
),
),
),
class ServicesForNewsPage {
  static const String url =
      "https://livetvapi.apyhi.com/api/v3/home?pageLocation=News&countries=IN&app_version=13&"
      "user_id=44edc2c905ae163f&package_id=livetv.movies.freemovies.watchtv.tvshows&os_platform=android";

  static Future<NewsPage> loadObjectList() async {
    var res = await http
        .get(url, headers: {'Authorization': dartJsonWebTokenGenerator()});

    if (res.statusCode == 200) {
      // print("response is there for news Page");
      final newsPageObjectList = newsPageFromJson(res.body);

      return newsPageObjectList;
    } else {
      print("no response");
      return null;
    }
  }
}

    List<Widget> wdgs_option = [
      HomePageForBottomNavigator(),
      MoviesPageForBottomNavigator(),
      TvSHowsPageOfBottomNavigator(),
      MusicPageofBottomNavigator(),
      // NewsPageOfBottomNavigator(), //dummy for now
      NewsPageOfBottomNavigator(),
      LifeStylePageOfBottomNavigator(),
      SportsPageOfBottomNavigator()
    ];

    if (_selectedIndex == 0) {
      wdgs_option = HomePageForBottomNavigator();
    } else if (hi == _selectedIndex) {
      wdgs_option = MoviesPageForBottomNavigator();
    } else if (){}

    List<int Function()> wdgs_option = [
      () => HomePageForBottomNavigator(),
      () => MoviesPageForBottomNavigator(),
      () => ...
    ];

    int val = c[1]();

SingleChildScrollView(
  controller: _scrollController,
  child: wdgs_option.elementAt(_selectedIndex),
)

SingleChildScrollView(
  controller: _scrollController,
  child: wdgs_option[_selectedIndex](),
)