多布局功能代码：

@override void initState() {  // TODO: implement initState  super.initState();  // 获取网络数据 一个banner 一个列表  initBannerData();  initHomeList(); } @override Widget build(BuildContext context) {  Widget itemColor = Divider(   color: Colors.blue,  );  Widget nullColor = Divider(   color: Colors.white,  );  return ListView.separated(   itemCount: _homeListBeanEntity.data.datas.length,   itemBuilder: (BuildContext context, int index) {   // 根据规则，抽取banner方法和listitem    return _bannerBeanData != null && _bannerBeanData.data.length > 0&&index==0      ? bannerItem(_bannerBeanData)      : listItem(_homeListBeanEntity, index);   },   separatorBuilder: (BuildContext context, int index) {    return index > 0 ? itemColor : nullColor;   },  ); }

void initBannerData() async {  result = await getNetWorkData("https://www.wanandroid.com/banner/json");  print("list=" + result);  if (result.toString().length > 0) {   BannerBeanEntity bannerBeanEntity =     BannerBeanEntity.fromJson(json.decode(result));   if (bannerBeanEntity != null) {    setState(() {     _bannerBeanData = bannerBeanEntity;    });   }  } }getNetWorkData(String url) async {  var uri = Uri.parse(url);  HttpClient httpClient = new HttpClient();  HttpClientRequest request = await httpClient.getUrl(uri);  HttpClientResponse httpClientResponse = await request.close();  var str = await httpClientResponse.transform(utf8.decoder).join();  print(httpClientResponse.toString());  return str; } void initHomeList() async {  result =await getNetWorkData("https://www.wanandroid.com/article/list/0/json");  print("list=" + result);  if (result.toString().length > 0) {   HomeListBeanEntity homeListBeanEntity =     HomeListBeanEntity.fromJson(json.decode(result));   if (homeListBeanEntity != null) {    setState(() {     _homeListBeanEntity = homeListBeanEntity;    });   }  } }