zhiying_base_widget/lib/pages/search_page/search_page2.dart

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'bloc/search_bloc.dart';
import 'bloc/search_repository.dart';
import 'package:zhiying_comm/zhiying_comm.dart';

class SearchPage2 extends StatelessWidget {
  final Map<String, dynamic> data;

  const SearchPage2(this.data);

  @override
  Widget build(BuildContext context) {
    return BlocProvider<SearchBloc>(
      create: (_) => SearchBloc(repository: SearchRepository())..add(SearchInitEvent(model: data)),
      child: SearchPage2Container(),
    );
  }
}

class SearchPage2Container extends StatefulWidget {
  @override
  _SearchPage2ContainerState createState() => _SearchPage2ContainerState();
}

class _SearchPage2ContainerState extends State<SearchPage2Container> {

  TabController _controller;

  @override
  void initState() {
    _controller = TabController(length: tabTitle.length, vsync: ScrollableState());
    super.initState();
  }

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

  @override
  Widget build(BuildContext context) {
    return MediaQuery.removePadding(
      removeTop: true,
      context: context,
      child: Container(
        width: double.infinity,
        child: BlocConsumer<SearchBloc, SearchState>(
          listener: (BuildContext context, SearchState state) {
            if (state is SearchErrorState) {
              print('数据加载出错');
            }
          },
          buildWhen: (previous, current) {
            /// 数据加载出错不进行build
            if (current is SearchErrorState) {
              return false;
            }

            /// 搜索成功，跳转结果页面
            if (current is SearchSubmitSuccessState) {
              return false;
            }

            /// 搜索失败，不进行build
            if (current is SearchSubmitErrorState) {
              return false;
            }

            return true;
          },
          builder: (context, state) {
            print('currente state = $state');
            if (state is SearchLoadedState) {
              return _getMainWidget(state?.model);
            }

            /// 骨架屏幕
            return _getMainWidget(null);
          },
        ),
      ),
    );
  }

  /// 主视图
  Widget _getMainWidget(List<Map<String, dynamic>> datas){
    return Scaffold(
      backgroundColor: Colors.white,
      body: NestedScrollView(
        headerSliverBuilder: (context, bool){
          return _createHeadWidget(context, datas);
        },
        body: ListView(
          children: <Widget>[
            Text('sss')
          ],
        ),
      ),
    );
  }


  /// 头部视图
  List<Widget> _createHeadWidget(BuildContext context, List<Map<String, dynamic>> datas){
    List<Widget> list = [];

    int length = datas?.length?? 0;
    if (length <= 0) {
      list.add(SliverToBoxAdapter(
        child: Container(
          height: 200,
          child: Center(
            child: Text('暂时无数据哦~'),
          ),
        ),
      ));
      return list;
    }

    for (int i = 0; i < 2; i++) {
      WidgetModel item = WidgetModel.fromJson(Map<String, dynamic>.from(datas[i]));
      print('item.modName ${item.modName}');
      list.addAll(WidgetFactory.create(
        item.modName,
        isSliver: true,
        model: datas[i],
      ));
    }
    list.add(_getTabbar());
    return list;

  }

  var tabTitle = [
    '页面1',
    '页面2',
    '页面3',
  ];

  Widget _getTabbar(){
    /// 悬停TabBar
    return SliverPersistentHeader(
      delegate: new SliverTabBarDelegate(
        TabBar(
          controller: _controller,
          tabs: tabTitle.map((f) => Tab(text: f)).toList(),
          indicatorColor: Colors.red,
          unselectedLabelColor: Colors.black,
          labelColor: Colors.red,
        ),
      ),
      pinned: true,
    );
  }

}

class SliverTabBarDelegate extends SliverPersistentHeaderDelegate {
  final TabBar widget;


  const SliverTabBarDelegate(this.widget)
      : assert(widget != null);

  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container( color:Colors.white,child: this.widget);
  }

  @override
  bool shouldRebuild(SliverTabBarDelegate oldDelegate) {
    return false;
  }

  @override
  double get maxExtent => widget.preferredSize.height;

  @override
  double get minExtent => widget.preferredSize.height;
}