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flutter - 在flutter中调用api后小部件没有重建

问题描述

观看此视频以正确理解问题。

当我构建项目时，小部件没有显示，但是当我重新保存项目时，小部件正在显示。我在下面给出我的代码。

（这是保存到每个页面的路由的主文件）

import 'package:flutter/material.dart';
import 'package:player_profile/first.dart';
import 'package:player_profile/second.dart';
import 'package:player_profile/third.dart';

void main() {
  runApp(MaterialApp(
    initialRoute: '/first',
    routes: {
      '/first': (context) => First(),
      '/second': (context) => Second(),
      '/third': (context) => Third()
    },
  ));
}

（这是应用程序的第一页，其中包含所有团队数据的小部件列表。单击团队的小部件后，它将转到第二页）

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:player_profile/teamData.dart';
import 'dart:convert' as convert;

class First extends StatefulWidget {
  @override
  _FirstState createState() => _FirstState();
}

class _FirstState extends State<First> {
  List<Widget> teamList = [];

  void getTeamList() async {
    var url = Uri.parse('https://www.balldontlie.io/api/v1/teams');
    http.Response response = await http.get(url);
    if (response.statusCode == 200) {
      var jsonData = convert.jsonDecode(response.body) as Map<String, dynamic>;

      if (jsonData['data'] != null) {
        jsonData['data'].forEach((v) {
          // teamData.add(new TeamData.fromJson(v));
          teamList.add(Padding(
            padding: const EdgeInsets.all(8.0),
            // ignore: deprecated_member_use
            child: RaisedButton(
                onPressed: () {
                  Navigator.pushNamed(context, '/second');
                },
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    Text(
                      'Name : ${TeamData.fromJson(v).name}',
                      style: TextStyle(
                        color: Colors.red,
                        fontSize: 15.0,
                      ),
                    ),
                    Text(
                      'Abbreviation : ${TeamData.fromJson(v).abbreviation}',
                      style: TextStyle(
                        color: Colors.blue,
                        fontSize: 15.0,
                      ),
                    ),
                    Text(
                      'City : ${TeamData.fromJson(v).city}',
                      style: TextStyle(
                        color: Colors.blue,
                        fontSize: 15.0,
                      ),
                    ),
                    Text(
                      'Conference : ${TeamData.fromJson(v).conference}',
                      style: TextStyle(
                        color: Colors.blue,
                        fontSize: 15.0,
                      ),
                    ),
                    Text(
                      'Division : ${TeamData.fromJson(v).division}',
                      style: TextStyle(
                        color: Colors.blue,
                        fontSize: 15.0,
                      ),
                    )
                  ],
                )),
          ));
        });
      }
    }
  }

  @override
  void initState() {
    super.initState();
    getTeamList();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        backgroundColor: Colors.black,
        appBar: AppBar(
          title: Text('Team'),
        ),
        body: GridView.count(
          crossAxisCount: 2,
          children: teamList,
        ));
  }
}

（这是应用程序的第二页，其中包含从 http 调用接收到的所有播放器详细信息小部件。它从 http 接收数据但小部件未显示。小部件仅在重新保存项目后显示。在 setState() 之后它不会重新构建这页纸。）

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert' as convert;
import 'package:player_profile/singlePlayer.dart';

class Second extends StatefulWidget {
  @override
  _SecondState createState() => _SecondState();
}

class _SecondState extends State<Second> {
  List<SinglePlayerData> playersList = [];
  List<Widget> showPlayers = [];

  getAllPlayers() async {
    var url = Uri.parse('https://www.balldontlie.io/api/v1/players');
    http.Response response = await http.get(url);
    if (response.statusCode == 200) {
      var jsonData = convert.jsonDecode(response.body) as Map<String, dynamic>;

      jsonData['data'].forEach((v) {
        SinglePlayerData playerData = SinglePlayerData(
            v['id'],
            v['first_name'],
            v['height_feet'],
            v['height_inches'],
            v['last_name'],
            v['position'],
            v['weight_pounds'],
            v['team']['id'],
            v['team']['abbreviation'],
            v['team']['city'],
            v['team']['conference'],
            v['team']['division'],
            v['team']['full_name'],
            v['team']['name']);
        playersList.add(playerData);
        setState(() {
          print('setState');
          showPlayers.add(Padding(
            padding: const EdgeInsets.all(8.0),
            // ignore: deprecated_member_use
            child: RaisedButton(
                onPressed: () {
                  Navigator.pushNamed(context, '/third',
                      arguments: {'data': playerData});
                },
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    Container(
                        height: 75.0,
                        width: 75.0,
                        child: Image(image: AssetImage('images/player2.png'))),
                    Padding(
                      padding: const EdgeInsets.all(5.0),
                      child: Text(
                        'Name : ${playerData.firstName} ${playerData.lastName}',
                        style: TextStyle(fontSize: 15.0, color: Colors.red),
                      ),
                    ),
                    Text(
                      'Team : ${playerData.name}',
                      style: TextStyle(fontSize: 15.0, color: Colors.blue),
                    ),
                    Padding(
                      padding: const EdgeInsets.all(5.0),
                      child: Text(
                        'Position : ${playerData.position}',
                        style: TextStyle(fontSize: 15.0, color: Colors.purple),
                      ),
                    )
                  ],
                )),
          ));
        });
      });
      print(playersList[1].firstName);
    }
  }

  @override
  void initState() {
    print('initState');
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    print('build');
    getAllPlayers();
    return Scaffold(
        backgroundColor: Colors.black,
        appBar: AppBar(
          title: Text('Players'),
        ),
        body: GridView.count(
          crossAxisCount: 2,
          children: showPlayers,
        ));
  }
}

（这是玩家详细数据的模型类）

class TeamData {
  int? id;
  String? abbreviation;
  String? city;
  String? conference;
  String? division;
  String? fullName;
  String? name;

  TeamData(this.id, this.abbreviation, this.city, this.conference,
      this.division, this.fullName, this.name);

  TeamData.fromJson(Map<String, dynamic> json)
      : id = json['id'],
        abbreviation = json['abbreviation'],
        city = json['city'],
        conference = json['conference'],
        division = json['division'],
        fullName = json['full_name'],
        name = json['name'];

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['abbreviation'] = this.abbreviation;
    data['city'] = this.city;
    data['conference'] = this.conference;
    data['division'] = this.division;
    data['full_name'] = this.fullName;
    data['name'] = this.name;
    return data;
  }
}

标签： flutterflutter-layoutflutter-dependenciesflutter-android

解决方案

我想你只需要setState((){});在结束时打电话getTeamList()

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