【发布时间】：2021-04-03 18:18:28
【问题描述】：
我是 Flutter 的初学者，我有一个 api，我使用 Navigator 将数据传递给这个 Route，它工作正常，但只有当我在 build 方法中调用参数时，在 build 方法之外，它们无法被识别，我的目标是在构建方法之外使用我的参数，以便能够创建一个使用 id 参数的 api 调用。问题出在 getClubs 方法和 InitState 方法中
这是我尝试过的
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'club_arguments.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
class ClubDetails extends StatefulWidget {
final int id;
final String name;
final String image;
final String rank;
final String nationality;
final String stadium;
final String manager;
final String wins;
final String draws;
final String losses;
final int goals;
final int goalsIn;
ClubDetails({ this.id, this.name,this.image,this.rank,this.nationality,this.stadium,this.manager,this.wins,this.draws,this.losses,this.goals,this.goalsIn});
@override
_ClubDetailsState createState() => _ClubDetailsState();
}
class _ClubDetailsState extends State<ClubDetails> {
String stadium;
String founded;
getClub(int id) async {
http.Response response = await http.get(
'http://api.football-data.org/v2/teams/$id',
headers: {'X-Auth-Token': '86014f6025ae430dba078acc94bb2647'});
String body = response.body;
Map data = jsonDecode(body);
stadium = data['name'];
//Club(this.id,this.name,this.image,this.rank,this.nationality,this.stadium,this.manager,this.wins,this.draws,this.losses,this.goals,this.goalsIn);
setState(() {
//print(data[0]['venue']);
print(stadium);
});
}
@override
void initState() {
super.initState();
getClub(widget.id);
print(widget.id);
}
@override
Widget build(BuildContext context) {
List<Titles> titles = [
Titles("LA LIGA", "Spain","Barcelona","2008" ),
];
return Scaffold(
appBar: AppBar(
title: Text("Club Info"),
backgroundColor: Colors.blue[300],
elevation: 0.0,
),
body: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.centerLeft,
end: Alignment.centerRight,
colors: [Colors.purple, Colors.blue])
),
child: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topLeft,
end: Alignment.bottomRight,
colors: [Colors.purple, Colors.black38])),
child: ListView(
children: [
SizedBox(
height: 20,
),
Container(
width: double.infinity,
child: Card(
elevation: 4.0,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0),
),
child: Padding(
padding: const EdgeInsets.all(16.0),
child:
Row(
children: <Widget>[
Container(
height: 40,
width: 40,
child:
SvgPicture.network(widget.image,
),
),
const SizedBox(width:10.0),
Spacer(),
Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget> [
Text(widget.name, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0,
)),
const SizedBox(height: 5.0, ),
Text("rank : "+widget.rank, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0,
)),
const SizedBox(height: 5.0, ),
Text("Found : "+widget.manager, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0,
)),
const SizedBox(height: 5.0, ),
Text("Nationality : "+widget.nationality, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0, color: Colors.grey[600],
)),
const SizedBox(height: 5.0, ),
Text("Stadium : "+widget.stadium, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0, color: Colors.grey[600],
)),
],
),
],
),
),
),
),
SizedBox(
height: 10,
),
Container(
margin: EdgeInsets.fromLTRB(10, 0, 0, 10),
child: Text(
"Achieved Titles",
style: TextStyle(fontSize: 17, fontWeight: FontWeight.w900, color: Colors.white),
),
),
SizedBox(
height: 10,
),
Container(
margin: EdgeInsets.fromLTRB(5, 0, 5, 0),
child: ListView.builder(
shrinkWrap: true,
physics : NeverScrollableScrollPhysics(),
itemBuilder: (context, index){
return Card(
elevation: 4.0,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0),
),
child: Padding(
padding: const EdgeInsets.all(16.0),
child:
Row(
children: <Widget>[
CircleAvatar(
backgroundImage: NetworkImage("https://www.impacttrophies.co.uk/content/images/thumbs/0065685_tower-football-trophy-gold.jpeg"),
),
const SizedBox(width:10.0),
Spacer(),
Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget> [
Text(titles[index].name, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0,
)),
const SizedBox(height: 5.0, ),
Text("country : "+titles[index].country, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0, color: Colors.grey[600],
)),
const SizedBox(height: 5.0, ),
Text("club : "+titles[index].club, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0, color: Colors.grey[600],
)),
const SizedBox(height: 5.0, ),
Text("year : "+titles[index].year, style: TextStyle( fontWeight:FontWeight.bold,
fontSize: 18.0, color: Colors.grey[600],
)),
],
),
],
),
),
);
},
itemCount: titles.length,
),
),
SizedBox(
height: 70,
),
],
),
)
),
);
}
}
class Stats{
String title;
String result;
Stats(this.title,this.result);
}
class Team {
String name;
String image;
String date;
Team(this.name,this.image,this.date);
}
class Titles {
String name;
String country;
String club;
String year;
Titles(this.name,this.country,this.club,this.year);
}
class Club {
int id;
String name;
String image;
String rank;
String nationality;
String stadium;
String manager;
String wins;
String draws;
String losses;
int goals;
int goalsIn;
Club(this.id, this.name, this.image, this.rank, this.nationality,
this.stadium, this.manager, this.wins, this.draws, this.losses,
this.goals, this.goalsIn);
}
我的目标是使用我的参数 id 作为参数调用我的方法 getClub，并使用我从请求 url 中的先前路由收到的 id 参数
【问题讨论】：
-
请分享您收到的错误。
-
错误是我在控制台中发现我的 json 值为 null，除了 id 值，当我在 initState 中使用 print 时，后端的所有值都是 null
-
我在使用查询结果时发现了这个错误：======== 小部件库捕获的异常================= ===================================== 在构建 ClubDetails(dirty, state: _ClubDetailsState) 时抛出以下 ArgumentError #fc3e7): Invalid argument(s) 相关的导致错误的小部件是：ClubDetails file:///C:/Users/Fares/AndroidStudioProjects/tl_fantasy/lib/clubs/club_navigation_bar.dart:33:42 抛出异常时，这是堆栈：#0 _StringBase.+ (dart:core-patch/string_patch.dart:267:57) ....
-
我会说你的后端有问题。使用 Postman 之类的其他工具对其进行测试。