flutter-go/lib/views/first_page/sub_page.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:flutter_go/components/list_view_item.dart';
import 'package:flutter_go/components/list_refresh.dart' as listComp;
import 'package:flutter_go/components/pagination.dart';
import 'package:flutter_go/views/first_page/first_page_item.dart';
import 'package:flutter_go/components/disclaimer_msg.dart';
import 'package:flutter_go/utils/net_utils.dart';

// ValueKey<String> key;

class SubPage extends StatefulWidget {
  @override
  SubPageState createState() => SubPageState();
}

class SubPageState extends State<SubPage> with AutomaticKeepAliveClientMixin{
  Future<SharedPreferences> _prefs = SharedPreferences.getInstance();
  Future<bool> _unKnow;
  GlobalKey<DisclaimerMsgState> key;

  @override
  bool get wantKeepAlive => true;


 @override
  void initState() {
    super.initState();
    if (key == null) {
       key = GlobalKey<DisclaimerMsgState>();
       // key = const Key('__RIKEY1__');
      //获取sharePre
       _unKnow = _prefs.then((SharedPreferences prefs) {
         return (prefs.getBool('disclaimer::Boolean') ?? false);
       });

      /// 判断是否需要弹出免责声明,已经勾选过不在显示,就不会主动弹
      _unKnow.then((bool value) {
         new Future.delayed(const Duration(seconds: 1),(){
           if (!value && key.currentState is DisclaimerMsgState && key.currentState.showAlertDialog is Function) {
             key.currentState.showAlertDialog(context);
           }
         });
      });
    }
  }


  Future<Map> getIndexListData([Map<String, dynamic> params]) async {
    const juejin_flutter = 'https://timeline-merger-ms.juejin.im/v1/get_tag_entry?src=web&tagId=5a96291f6fb9a0535b535438';
    var pageIndex = (params is Map) ? params['pageIndex'] : 0;
    final _param  = {'page':pageIndex,'pageSize':20,'sort':'rankIndex'};
    var responseList = [];
    var  pageTotal = 0;

    try{
      var response = await NetUtils.get(juejin_flutter, params: _param);
      responseList = response['d']['entrylist'];
      pageTotal = response['d']['total'];
      if (!(pageTotal is int) || pageTotal <= 0) {
        pageTotal = 0;
      }
    }catch(e){

    }
    pageIndex += 1;
    List resultList = new List();
    for (int i = 0; i < responseList.length; i++) {
      try {
        FirstPageItem cellData = new FirstPageItem.fromJson(responseList[i]);
        resultList.add(cellData);
      } catch (e) {
        // No specified type, handles all
      }
    }
    Map<String, dynamic> result = {"list":resultList, 'total':pageTotal, 'pageIndex':pageIndex};
    return result;
  }

  Widget makeCard(index,item){

    var myTitle = '${item.title}';
    var myUsername = '${'👲'}: ${item.username} ';
    var codeUrl = '${item.detailUrl}';
    return new ListViewItem(itemUrl:codeUrl,itemTitle: myTitle,data: myUsername,);
  }

  headerView(){
    return
      Column(
        children: <Widget>[
        Stack(
        //alignment: const FractionalOffset(0.9, 0.1),//方法一
        children: <Widget>[
            Pagination(),
            Positioned(//方法二
            top: 10.0,
            left: 0.0,
            child: DisclaimerMsg(key:key,pWidget:this)
            ),
          ]),
        SizedBox(height: 1, child:Container(color: Theme.of(context).primaryColor)),
        SizedBox(height: 10),
        ],
      );

  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return new Column(
        children: <Widget>[
          new Expanded(
            child: listComp.ListRefresh(getIndexListData,makeCard)
          )
        ]
    );
  }
}