app/lib/widgets/weather_page/weather_city_page.dart

import 'package:azlistview/azlistview.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';
import 'package:recook/base/base_store_state.dart';
import 'package:recook/constants/header.dart';
import 'package:recook/constants/styles.dart';
import 'package:recook/widgets/custom_app_bar.dart';
import 'package:recook/widgets/weather_page/weather_city_model.dart';
import 'package:recook/widgets/weather_page/weather_city_tool.dart';

class WeatherCityPage extends StatefulWidget {
  final Map arguments;
  WeatherCityPage({Key key, this.arguments}) : super(key: key);
  static setArguments(String cityName,){
    return {
      "cityName": cityName,
    };
  }
  @override
  _WeatherCityPageState createState() => _WeatherCityPageState();
}

class _WeatherCityPageState extends BaseStoreState<WeatherCityPage> {
  int _suspensionHeight = 40;
  int _itemHeight = 50;
  String _suspensionTag = "";
  List<WeatherCityModel> _cityList = [];
  String _selectCity = "";
  List<WeatherCityModel> _searchResultCityList = [];
  TextEditingController _textEditingController;
  FocusNode _focusNode = FocusNode();

  @override
  void initState() {
    _textEditingController = TextEditingController();
    _focusNode.addListener((){
      setState(() {});
    });
    String cityName = widget.arguments['cityName'];
    if (!TextUtils.isEmpty(cityName)) _selectCity = cityName;
    WeatherCityTool.getInstance().getCityList().then((onValue){
      _cityList = onValue;
      setState(() {});
    });
    super.initState();
  }

  @override
  Widget buildContext(BuildContext context, {store}) {
    return Scaffold(
      resizeToAvoidBottomPadding: false,
      appBar: CustomAppBar(
        appBackground: Colors.white,
        title: "选择城市",
        themeData: AppThemes.themeDataGrey.appBarTheme,
        elevation: 0,
      ),
      body: Container(
        color: Colors.white,
        // color: AppColor.frenchColor,
        child: Column(
          children: <Widget>[
            _searchBar(),
            _focusNode.hasFocus || !TextUtils.isEmpty(_textEditingController.text) ? 
            Expanded(child: _resultWidget())
            : Expanded(
              child: Column(
                children: <Widget>[
                  GestureDetector(
                    onTap: (){
                      if (TextUtils.isEmpty(_selectCity)) return;
                      
                      WeatherCityModel model = WeatherCityModel();
                      model.cityZh = _selectCity;
                      Navigator.pop(context, model);
                    },
                    child: Container(
                      alignment: Alignment.centerLeft,
                      padding: const EdgeInsets.only(left: 15.0),
                      height: 50.0,
                      child: Text("当前定位城市: $_selectCity", style: TextStyle(color: Colors.black,fontSize: 14 ),),
                    ),
                  ),
                  Expanded(
                    child: AzListView(
                      shrinkWrap: false,
                      data: _cityList,
                      topData: null,
                      itemBuilder: (context, model) => _buildListItem(model),
                      suspensionWidget: _buildSusWidget(_suspensionTag),
                      isUseRealIndex: true,
                      itemHeight: _itemHeight,
                      suspensionHeight: _suspensionHeight,
                      onSusTagChanged: (tag){
                        setState(() {
                          _suspensionTag = tag;
                        });
                      },
                    ),
                  )
                ],
              ),
            )
          ],
        ),
      ),
    );
  }

  ///构建列表 item Widget.
  Widget _buildListItem(WeatherCityModel model) {
    return Column(
      children: <Widget>[
        Offstage(
          offstage: !(model.isShowSuspension == true),
          child: _buildSusWidget(model.getSuspensionTag()),
        ),
        SizedBox(
          height: _itemHeight.toDouble(),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              GestureDetector(
                onTap: (){
                  Navigator.pop(context, model);
                },
                child: Container(
                  color: Colors.white,
                  alignment: Alignment.centerLeft,
                  padding: EdgeInsets.only(left: 15),
                  height: _itemHeight.toDouble()-1,
                  child: Text(model.cityZh, style: TextStyle(color: Colors.black,fontSize: ScreenAdapterUtils.setSp(15) ),),
                ),
              ),
              Container(
                margin: EdgeInsets.only(left: 15,),
                color: AppColor.frenchColor,
                height: 1,
              )
            ],
          ),
        ),
      ],
    );
  }
  ///构建悬停Widget.
  Widget _buildSusWidget(String susTag) {
    return Container(
      height: _suspensionHeight.toDouble(),
      padding: const EdgeInsets.only(left: 15.0),
      color: Color(0xfff3f4f5),
      alignment: Alignment.centerLeft,
      child: Text(
        '$susTag',
        softWrap: false,
        style: TextStyle(
          fontSize: 14.0,
          color: Color(0xff999999),
        ),
      ),
    );
  }

  _searchBar(){
    return Container(
      height: 45, width: MediaQuery.of(context).size.width,
      padding: EdgeInsets.symmetric(horizontal: 15, vertical: 5),
      child: Container(
        decoration: BoxDecoration(
          color: Color(0xfff3f4f5),
          borderRadius: BorderRadius.circular(5)
        ),
        child: Row(
          children: <Widget>[
            Container(
              margin: EdgeInsets.only(left: 10),
              child: Image.asset("assets/search.png", width: 22, height: 22,),
            ),
            Expanded(
              child: CupertinoTextField(
                decoration: BoxDecoration(
                  color: Colors.white.withAlpha(0)
                ),
                controller: _textEditingController,
                focusNode: _focusNode,
                keyboardType: TextInputType.text,
                textInputAction: TextInputAction.search,
                placeholder: "请输入搜索词...",
                placeholderStyle: TextStyle(color: Color(0xff999999), fontSize: 14, fontWeight: FontWeight.w300),
                onSubmitted: (text){
                  // WeatherCityTool.getInstance().searchWithQuery(text, (list){
                  //   _searchResultCityList = list;
                  //   setState(() {});
                  // });
                },
                onChanged: (text){
                  WeatherCityTool.getInstance().searchWithQuery(text, (list){
                    _searchResultCityList = list;
                    setState(() {});
                  });
                },
              ),
            )
          ],
        ),
      ),
    );
  }
  _resultWidget(){
    return Container(
      child: _searchResultCityList.length <= 0?
      GestureDetector(
        onTap: () => FocusScope.of(context).requestFocus(FocusNode()),
        child: noDataView("没有数据..."),
      )
      : ListView.builder(
        itemCount: _searchResultCityList.length,
        itemBuilder: (BuildContext context, int index) {
        return _buildListItem(_searchResultCityList[index]);
       },
      ),
    );
  }
}