Flutter的ListVIew获取并动态展示JSON数据

今朝.122

2024-04-18 帮助1人

插件配置
dio: ^4.0.4

信息获取——netConfig类

import 'dart:io';
import 'package:dio/dio.dart';
class NetConfig{
static String baseurl="http://localhost:8888/articleList/pageview_article";
//接口地址，与后台交互
static getArticle() async {//异步处理
try{
// ignore: unused_local_variable
var response =await Dio().post(baseurl);//发送post请求，获取接口返回的数据
if(response.statusCode==200){//判断是否请求成功
return response;
}
}catch(e){ //捕获异常
// ignore: avoid_print
print(e.toString());
}
return null;
}
}

NetConfig这个类中，可以定义很多与后台交互的方法，这里为了展示我只定义了一个方法getArticle()，为了方便我将方法定义为了静态方法，同时为了避免不必要的错误，使用了异步处理await前缀（注意在使用此前缀时，方法上必须加上async异步字样），然后就是调用了Dio的网络通信来获取数据

方法使用——ListViewDemo类

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:patient_project/utils/NetConfig.dart';
import 'package:patient_project/utils/articleUsertoken.dart';
class ListViewDemo extends StatefulWidget {
const ListViewDemo({ Key key }) : super(key: key);
@override
State<ListViewDemo> createState() => _ListViewDemoState();
}
class _ListViewDemoState extends State<ListViewDemo> {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Demo'),
),
body: FutureBuilder(//处理异步数据
future: NetConfig.getArticle(),//调用NetConfig的getArticle方法
builder: (context,snapshot){
if(snapshot.hasData){//判断是否有数据
var _data=jsonDecode(snapshot.data.toString());
//这里返回的时json格式数据，所以要对数据进行解码，jsonDecode是convert中的一个类用来对json解码
var article=articleToken.fromJson(_data);
//解码后的数据转实体类
return ListView.builder(
itemCount: article.data.length,//数据的长度
itemBuilder: (context,index){
return Container(
child: Text(article.data[index].articleTitle),
);
},
);
}else{
Text("no data");
}
},
),
);
}
}

为了大家方便理解我使用了有状态管理（当然大家也可以用getX来编写更方便哦），FutureBuilder是flutter处理异步数据常用的方法，future属性可以调用一个异步方法，builder属性里面可以进行数据处理，比如判断数据是否为空，因为这里返回的时json格式数据，所以要对数据进行解码，jsonDecode是convert中的一个类用来对json解码，同时为了方便后面操作，我将解码后的json转成了实体类，可以搜一下JSON to Dart Converter - Convert JSON Code Online，具体使用如下

学新通

好的原理我们已经讲完了，下面开始正式操作

实体类articleToken

class articleToken {
bool success;
int code;
String msg;
List<Data> data;
articleToken({this.success, this.code, this.msg, this.data});
articleToken.fromJson(Map<String, dynamic> json) {
success = json['success'];
code = json['code'];
msg = json['msg'];
if (json['data'] != null) {
data = <Data>[];
json['data'].forEach((v) {
data.add(new Data.fromJson(v));
});
}
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['success'] = this.success;
data['code'] = this.code;
data['msg'] = this.msg;
if (this.data != null) {
data['data'] = this.data.map((v) => v.toJson()).toList();
}
return data;
}
}
class Data {
int id;
String emailuser;
String username;
String articleTitle;
String isattention;
String isComment;
String content;
int agree;
int disagree;
int comment;
int sharecount;
String imageurl;
String articletime;
int viewCounts;
// String? articleTime;
// String? articleTitle;
// String? imageUrl;
Data(
{this.id,
this.emailuser,
this.username,
this.articleTitle,
this.isattention,
this.isComment,
this.content,
this.agree,
this.disagree,
this.comment,
this.sharecount,
this.imageurl,
this.articletime,
this.viewCounts,
// this.articleTime,
// this.articleTitle,
// this.imageUrl
});
Data.fromJson(Map<String, dynamic> json) {
id = json['id'];
emailuser = json['emailuser'];
username = json['username'];
articleTitle = json['articletitle'];
isattention = json['isattention'];
isComment = json['is_comment'];
content = json['content'];
agree = json['agree'];
disagree = json['disagree'];
comment = json['comment'];
sharecount = json['sharecount'];
imageurl = json['imageurl'];
articletime = json['articletime'];
viewCounts = json['view_counts'];
// articleTime = json['article_time'];
// articleTitle = json['article_title'];
// imageUrl = json['image_url'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['id'] = this.id;
data['emailuser'] = this.emailuser;
data['username'] = this.username;
data['articletitle'] = this.articleTitle;
data['isattention'] = this.isattention;
data['is_comment'] = this.isComment;
data['content'] = this.content;
data['agree'] = this.agree;
data['disagree'] = this.disagree;
data['comment'] = this.comment;
data['sharecount'] = this.sharecount;
data['imageurl'] = this.imageurl;
data['articletime'] = this.articletime;
data['view_counts'] = this.viewCounts;
// data['article_time'] = this.articleTime;
// data['article_title'] = this.articleTitle;
// data['image_url'] = this.imageUrl;
return data;
}
}

主界面

import 'dart:convert';
import 'package:dio/dio.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:date_format/date_format.dart';
import 'package:get/get.dart';
import 'package:patient_project/Home/details/details_Conditions/chat.dart';
import 'package:patient_project/utils/Color.dart';
import 'package:patient_project/utils/articleUsertoken.dart';
class ArticleShow extends StatefulWidget {
@override
State<ArticleShow> createState() => _ArticleListState();
}
class _ArticleListState extends State<ArticleShow> {
Color color = Colors.red.shade900;
// ignore: prefer_typing_uninitialized_variables
static Map<String, dynamic> json;
String guanzhu = "关注";
DateTime dateTime = DateTime.now();
Icon icon = Icon(Icons.add);
Widget Rowdate(
BuildContext context, double scale, Data data, String anniutitle) {
return Row(
// crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Container(
child: new Text('${data.username}',
style:
TextStyle(fontSize: 20 * scale, fontWeight: FontWeight.w700)),
),
SizedBox(
width: 100 * scale,
),
new Text(
data.articletime,
// formatDate(DateTime.now(),
// [yyyy, "-", mm, "-", dd, " ", HH, ":", nn, ":", ss]),
style: Theme.of(context).textTheme.subtitle2,
),
SizedBox(
width: 400 * scale,
),
RaisedButton(
color: Colors.red,
textColor: Colors.red,
child: Row(
children: <Widget>[
Icon(Icons.add, color: Colors.white),
SizedBox(
width: 15 * scale,
),
Text(
"关注",
style: TextStyle(
color: Colors.white,
fontSize: 10 * scale,
),
),
],
),
shape: RoundedRectangleBorder(
side: BorderSide(
color: Colors.white,
width: 1 * scale,
),
borderRadius: BorderRadius.circular(8 * scale)),
// onPressed: () {
// setState(() {
// if (acticle.isattention=="false") {
// color = Colors.grey.shade600;
// guanzhu = "已关注";
// icon = Icon(Icons.add_task);
// acticle.isattention = "true";
// } else {
// Color color = Colors.red.shade900;
// String guanzhu = "关注";
// }
// });
// // Navigator.of(context).pushNamed('/Sign');
// },
),
],
);
}
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
double scale = size.width / 1920;
double sizeWidth = MediaQuery.of(context).size.width;
double sizeHeight = MediaQuery.of(context).size.height;
return SingleChildScrollView(
child: ArticleShowList(scale, sizeWidth, sizeHeight, context),
);
}
Future getArticle() async {
try {
String articleUrl = "http://localhost:8888/articleList/pageview_article";
Dio dio = new Dio();
print("开始请求数据");
var response = await dio.post(articleUrl);
if (response.statusCode == 200) {
return response;
}
print("请求完成");
} catch (e) {
print(e.toString());
}
return null;
}
// List<Data> getlist() {
// getArticle().then((result) {
// json = jsonDecode(result.toString());
// }).whenComplete(() {
// print("异步任务处理完成");
// print(json['data']);
// articleToken content = articleToken.fromJson(json);
// print(content.data[1].emailuser);
// return content.data;
// }).catchError(() {
// print("出现异常了");
// });
// }
ArticleShowList(
double scale, double sizeWidth, double sizeHeight, BuildContext context) {
// List<Data> list = getlist();
return FutureBuilder(
future: getArticle(),
builder: (context, snapshot) {
if (snapshot.hasData) {
var _data = jsonDecode(snapshot.data.toString());
var _content = articleToken.fromJson(_data);
return Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
padding: EdgeInsets.all(10),
// height: sizeHeight,
width: 1200 * scale,
// alignment: Alignment.center,
// decoration: BoxDecoration(color: Colors.amber),
child: Container(
height: sizeHeight,
child: ListView.builder(
itemCount: 5,
itemBuilder: (context, index) {
print(_content.data[index].articleTitle);
return Card(
elevation: 10,
child: GestureDetector(
onTap: () {
Get.to(ChatView(),
arguments: {'data': _content.data[index]},
transition:Transition.zoom,
);
},
child: ListTile(
title: Text(
_content.data[index].articleTitle,
// articleContent.articlrTitle,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle: Container(
child: Column(
children: <Widget>[
SizedBox(
height: 10,
),
Row(
children: <Widget>[
Container(
height: 40 * scale,
width: 40 * scale,
margin:
const EdgeInsets.only(right: 16.0),
child: CircleAvatar(
backgroundImage: NetworkImage(
_content.data[index].imageurl),
),
),
// SizedBox(height: 10,),
Rowdate(context, scale,
_content.data[index], guanzhu)
],
),
SizedBox(
height: 10,
),
Container(
padding: EdgeInsets.only(bottom: 10),
child: Text(
_content.data[index].content,
overflow: TextOverflow.fade,
maxLines: 2,
)),
Row(
children: <Widget>[
RaisedButton(
color: Colors.blue[100],
textColor: Colors.white,
child: Row(
children: <Widget>[
Icon(Icons.sentiment_satisfied,
color: Colors.blue),
SizedBox(
width: 15 * scale,
),
Text(
"${'${_content.data[index].agree}'}同意",
style: TextStyle(
color: Colors.black,
fontSize: 10 * scale,
),
),
],
),
onPressed: () {},
),
SizedBox(
width: 10 * scale,
),
RaisedButton(
color: Colors.blue[100],
textColor: Colors.white,
child: Row(
children: <Widget>[
Icon(Icons.sentiment_dissatisfied,
color: Colors.blue),
SizedBox(
width: 15 * scale,
),
Text(
'${_content.data[index].disagree}反对',
style: TextStyle(
color: Colors.black,
fontSize: 10 * scale,
),
),
],
),
onPressed: () {
setState(() {
'$index';
});
// Navigator.of(context).pushNamed('/Sign');
},
),
SizedBox(
width: 150 * scale,
),
FlatButton(
color: Colors.white,
textColor: Colors.white,
child: Row(
children: <Widget>[
Icon(Icons.comment,
color: Colors.blue),
SizedBox(
width: 15 * scale,
),
Text(
"${'${_content.data[index].comment}'}条评论",
style: TextStyle(
color: Colors.black,
fontSize: 10 * scale,
),
),
],
),
onPressed: () {
setState(() {
'$index';
});
},
),
SizedBox(
width: 10 * scale,
),
FlatButton(
color: Colors.white,
textColor: Colors.white,
child: Row(
children: <Widget>[
Icon(Icons.share,
color: Colors.blue),
SizedBox(
width: 15 * scale,
),
Text(
"${_content.data[index].sharecount}次分享",
style: TextStyle(
color: Colors.black,
fontSize: 10 * scale,
),
),
],
),
onPressed: () {
setState(() {
index ;
});
// Navigator.of(context).pushNamed('/Sign');
},
),
SizedBox(
width: 10 * scale,
),
Text(
"${_content.data[index].agree}次收藏",
),
SizedBox(
width: 10 * scale,
),
FlatButton(
color: Colors.white,
textColor: Colors.white,
child: Row(
children: <Widget>[
Icon(
Icons.visibility,
color: Colors.yellow,
),
SizedBox(
width: 15 * scale,
),
Text(
"${_content.data[index].viewCounts}浏览",
style: TextStyle(
color: Colors.black,
fontSize: 10 * scale,
),
),
],
),
onPressed: () {
setState(() {
index ;
});
// Navigator.of(context).pushNamed('/Sign');
},
)
],
)
],
),
),
),
),
);
},
),
),
),
],
);
} else {
Text("no data");
}
},
);
}
}

效果展示

学新通

这篇好文章是转载于：学新通技术网

Flutter的ListVIew获取并动态展示JSON数据

插件配置

信息获取——netConfig类

方法使用——ListViewDemo类

实体类articleToken

主界面

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