解析JSON以在Dart中列出
我试图解析来自天气API的一些复杂JSON,并将其显示在列表视图中。我使用quickType为自己生成了一个模型,但似乎无法将数据解析为列表。我相当肯定,错误的主要部分是我在解析服务文件中的数据时的逻辑,因为来自API的数据是一个复杂的结构,我不知道如何解析。由于API数据的缘故,它被分成了两个映射或列表?小时和元。因此有一个额外的类。请帮帮我 以下是服务/解析文件:解析JSON以在Dart中列出,json,list,flutter,parsing,dart,Json,List,Flutter,Parsing,Dart,我试图解析来自天气API的一些复杂JSON,并将其显示在列表视图中。我使用quickType为自己生成了一个模型,但似乎无法将数据解析为列表。我相当肯定,错误的主要部分是我在解析服务文件中的数据时的逻辑,因为来自API的数据是一个复杂的结构,我不知道如何解析。由于API数据的缘故,它被分成了两个映射或列表?小时和元。因此有一个额外的类。请帮帮我 以下是服务/解析文件: import 'weather_model.dart'; import 'package:http/http.dart' a
import 'weather_model.dart';
import 'package:http/http.dart' as http;
import 'dart:io';
class Service {
static const lat = '-33.7506';
static const lng = '18.4401';
static const params =
'swellDirection,windSpeed,windDirection,wavePeriod,waveHeight,airTemperature';
static Future<List<Hour>> getConditions() async {
try {
final response = await http.get(
Uri.encodeFull(
'https://api.stormglass.io/v2/weather/point?lat=$lat&lng=$lng¶ms=$params&start=2020-12-11&end=2020-12-12'),
headers: {
HttpHeaders.authorizationHeader:
'exampleapi'
});
if (200 == response.statusCode) {
final conditions = conditionsFromJson(response.body);
print(response.body);
return conditions.hours;
}
} catch (e) {
print('Not working');
return List<Hour>();
}
}
}
导入'weather_model.dart';
将“package:http/http.dart”导入为http;
导入“dart:io”;
班级服务{
静态常数lat='-33.7506';
静态常数lng='18.4401';
静态常量参数=
“膨胀、风速、风向、波周期、波高、气温”;
静态未来getConditions()异步{
试一试{
最终响应=等待http.get(
Uri.encodeFull(
'https://api.stormglass.io/v2/weather/point?lat=$lat&lng=$lng¶ms=$params&start=2020-12-11&end=2020-12-12’,
标题:{
HttpHeaders.authorizationHeader:
“示例API”
});
if(200==响应.状态码){
最终条件=conditionsFromJson(response.body);
打印(响应.正文);
返回条件。小时;
}
}捕获(e){
打印(“不工作”);
返回列表();
}
}
}
这是我的主要文件:
import 'package:flutter/material.dart';
import 'package:moreapi_practise/weather_model.dart';
import 'Service.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'My API Practice'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<Hour> _conditions;
bool _loading;
@override
void initState() {
super.initState();
_loading = true;
Service.getConditions().then((conditions) {
_conditions = conditions;
_loading = false;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(_loading ? 'Loading...' : 'Conditions'),
),
body: Container(child: ListView.builder(itemBuilder: (context, index) {
Hour condition = _conditions[index];
return ListTile(
title: Text('${condition.airTemperature}'),
);
})),
);
}
}
导入“包装:颤振/材料.省道”;
导入“package:moreapi_Practice/weather_model.dart”;
导入“Service.dart”;
void main(){
runApp(MyApp());
}
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:我的主页(标题:“我的API实践”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
列出条件;
bool_加载;
@凌驾
void initState(){
super.initState();
_加载=真;
Service.getConditions()然后((条件){
_条件=条件;
_加载=假;
});
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(_loading?'loading…':'Conditions'),
),
主体:容器(子:ListView.builder(itemBuilder:(上下文,索引){
小时条件=_条件[索引];
返回列表块(
标题:文本(“${condition.airTemperature}”),
);
})),
);
}
}
然后是我的模型:
// To parse this JSON data, do
//
// final conditions = conditionsFromJson(jsonString);
import 'dart:convert';
Conditions conditionsFromJson(String str) => Conditions.fromJson(json.decode(str));
String conditionsToJson(Conditions data) => json.encode(data.toJson());
class Conditions {
Conditions({
this.hours,
this.meta,
});
List<Hour> hours;
Meta meta;
factory Conditions.fromJson(Map<String, dynamic> json) => Conditions(
hours: List<Hour>.from(json["hours"].map((x) => Hour.fromJson(x))),
meta: Meta.fromJson(json["meta"]),
);
Map<String, dynamic> toJson() => {
"hours": List<dynamic>.from(hours.map((x) => x.toJson())),
"meta": meta.toJson(),
};
}
class Hour {
Hour({
this.airTemperature,
this.swellDirection,
this.time,
this.waveHeight,
this.wavePeriod,
this.windDirection,
this.windSpeed,
});
AirTemperature airTemperature;
SwellDirection swellDirection;
DateTime time;
SwellDirection waveHeight;
SwellDirection wavePeriod;
SwellDirection windDirection;
SwellDirection windSpeed;
factory Hour.fromJson(Map<String, dynamic> json) => Hour(
airTemperature: AirTemperature.fromJson(json["airTemperature"]),
swellDirection: SwellDirection.fromJson(json["swellDirection"]),
time: DateTime.parse(json["time"]),
waveHeight: SwellDirection.fromJson(json["waveHeight"]),
wavePeriod: SwellDirection.fromJson(json["wavePeriod"]),
windDirection: SwellDirection.fromJson(json["windDirection"]),
windSpeed: SwellDirection.fromJson(json["windSpeed"]),
);
Map<String, dynamic> toJson() => {
"airTemperature": airTemperature.toJson(),
"swellDirection": swellDirection.toJson(),
"time": time.toIso8601String(),
"waveHeight": waveHeight.toJson(),
"wavePeriod": wavePeriod.toJson(),
"windDirection": windDirection.toJson(),
"windSpeed": windSpeed.toJson(),
};
}
class AirTemperature {
AirTemperature({
this.noaa,
this.sg,
});
double noaa;
double sg;
factory AirTemperature.fromJson(Map<String, dynamic> json) => AirTemperature(
noaa: json["noaa"].toDouble(),
sg: json["sg"].toDouble(),
);
Map<String, dynamic> toJson() => {
"noaa": noaa,
"sg": sg,
};
}
class SwellDirection {
SwellDirection({
this.icon,
this.meteo,
this.noaa,
this.sg,
});
double icon;
double meteo;
double noaa;
double sg;
factory SwellDirection.fromJson(Map<String, dynamic> json) => SwellDirection(
icon: json["icon"].toDouble(),
meteo: json["meteo"] == null ? null : json["meteo"].toDouble(),
noaa: json["noaa"].toDouble(),
sg: json["sg"].toDouble(),
);
Map<String, dynamic> toJson() => {
"icon": icon,
"meteo": meteo == null ? null : meteo,
"noaa": noaa,
"sg": sg,
};
}
class Meta {
Meta({
this.cost,
this.dailyQuota,
this.end,
this.lat,
this.lng,
this.params,
this.requestCount,
this.start,
});
int cost;
int dailyQuota;
String end;
double lat;
double lng;
List<String> params;
int requestCount;
String start;
factory Meta.fromJson(Map<String, dynamic> json) => Meta(
cost: json["cost"],
dailyQuota: json["dailyQuota"],
end: json["end"],
lat: json["lat"].toDouble(),
lng: json["lng"].toDouble(),
params: List<String>.from(json["params"].map((x) => x)),
requestCount: json["requestCount"],
start: json["start"],
);
Map<String, dynamic> toJson() => {
"cost": cost,
"dailyQuota": dailyQuota,
"end": end,
"lat": lat,
"lng": lng,
"params": List<dynamic>.from(params.map((x) => x)),
"requestCount": requestCount,
"start": start,
};
}
//要解析此JSON数据,请执行以下操作
//
//最终条件=conditionsFromJson(jsonString);
导入“dart:convert”;
Conditions Conditions fromJson(String str)=>Conditions.fromJson(json.decode(str));
字符串conditionsToJson(Conditions data)=>json.encode(data.toJson());
阶级条件{
条件({
这个时间,
这个.meta,,
});
列出时间;
元元;
工厂条件。fromJson(映射json)=>条件(
小时数:List.from(json[“hours”].map((x)=>Hour.fromJson(x)),
meta:meta.fromJson(json[“meta”]),
);
映射到JSON()=>{
“小时”:List.from(hours.map((x)=>x.toJson()),
“meta”:meta.toJson(),
};
}
课时{
时辰({
这个,气温,
这个,膨胀,
这次,
这个,波高,
这段时间,,
这个,风向,
这个,风速,
});
气温;
膨胀膨胀;
日期时间;
膨胀波高;
膨胀波期;
膨胀风向;
膨胀风速;
factory Hour.fromJson(映射json)=>Hour(
airtimperature:airtimperature.fromJson(json[“airtimperature”]),
sweldirection:sweldirection.fromJson(json[“sweldirection”]),
时间:DateTime.parse(json[“time”]),
waveHeight:sweldirection.fromJson(json[“waveHeight”]),
wavePeriod:sweldirection.fromJson(json[“wavePeriod”]),
windDirection:sweldirection.fromJson(json[“windDirection”]),
windSpeed:sweldirection.fromJson(json[“windSpeed”]),
);
映射到JSON()=>{
“airtimperature”:airtimperature.toJson(),
“sweldirection”:sweldirection.toJson(),
“time”:time.toIso8601String(),
“waveHeight”:waveHeight.toJson(),
“wavePeriod”:wavePeriod.toJson(),
“windDirection”:windDirection.toJson(),
“windSpeed”:windSpeed.toJson(),
};
}
等级气温{
气温({
这是noaa,
这个是.sg,
});
双noaa;
双sg;
工厂空气温度.fromJson(映射json)=>空气温度(
noaa:json[“noaa”].toDouble(),
sg:json[“sg”].toDouble(),
);
映射到JSON()=>{
“noaa”:noaa,
“sg”:sg,
};
}
阶级膨胀{
膨胀({
这个图标,
这个,梅托,
这是noaa,
这个是.sg,
});
双图标;
双表;
双noaa;
双sg;
工厂膨胀方向.fromJson(映射json)=>膨胀方向(
icon:json[“icon”].toDouble(),
meteo:json[“meteo”]==null?null:json[“meteo”].toDouble(),
noaa:json[“noaa”].toDouble(),
sg:json[“sg”].toDouble(),
);
映射到JSON()=>{
“图标”:图标,
“meteo”:meteo==null?null:meteo,
“noaa”:noaa,
“sg”:sg,
};
}
类元{
元({
这是成本,
这是每日配额,
这,这,,
这个,拉特,
这是液化天然气,
这是params,
这是我的名字,
这个,开始,
});
国际成本;
国际每日配额;
弦端;
双洛杉矶
import 'package:flutter/material.dart';
import 'package:moreapi_practise/weather_model.dart';
import 'Service.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'My API Practice'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<Hour> _conditions;
bool _loading;
Future myFuture;
Future _getService() async {
await Service.getConditions().then((conditions) {
setState(() {
_conditions = conditions;
_loading = false;
});
});
}
@override
void initState() {
super.initState();
_loading = true;
myFuture = _getService();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(_loading ? 'Loading...' : 'Conditions'),
),
body: _loading
? const Center(
child: CircularProgressIndicator(),
)
: Container(
child: ListView.builder(
itemCount: _conditions.length,
itemBuilder: (context, index) {
final Hour condition = _conditions[index];
return ListTile(
title: Text(
'${condition.airTemperature.noaa} ${condition.airTemperature.sg}'),
);
},
),
),
);
}
}