自从昨天开始在我的项目上编码以来,我面临着同样的问题,该项目的一部分是从给定的api获取一些json数据。
我的api链接是:http : //alkadhum-col.edu.iq/wp-json/wp/v2/posts?_embed
我正在使用Flutter SDK,我很困惑为什么它不能与我一起使用!,我的工作是仅获取链接,标题和source_url对象,但我无法获取它。
我在flutter文档
https://flutter.dev/docs/cookbook/networking/fetch-data中尝试了以下代码,并根据我的需要进行了一些修改后没有任何数据。
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
Future<Post> fetchPost() async {
final response =
await http.get('http://alkadhum-col.edu.iq/wp-json/wp/v2/posts/');
if (response.statusCode == 200) {
// If the call to the server was successful, parse the JSON
return Post.fromJson(json.decode(response.body));
} else {
// If that call was not successful, throw an error.
throw Exception('Failed to load post');
}
}
class Post {
final int id;
String title;
String link;
Post({this.id, this.title, this.link});
factory Post.fromJson(Map<String, dynamic> json) {
return Post(
id: json['id'],
title: json['title'].toString(),
link: json['link'].toString()
);
}
}
void main() => runApp(MyApp(post: fetchPost()));
class MyApp extends StatelessWidget {
final Future<Post> post;
MyApp({Key key, this.post}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Fetch Data Example',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
appBar: AppBar(
title: Text('Fetch Data Example'),
),
body: Center(
child: FutureBuilder<Post>(
future: post,
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text(snapshot.data.link);
} else if (snapshot.hasError) {
return Text("${snapshot.error}");
}
// By default, show a loading spinner
return CircularProgressIndicator();
},
),
),
),
);
}
}
我只得到以下消息:
动态类型列表不是动态映射字符串类型的子类型
任何帮助将不胜感激。
提前致谢。
您的JSON响应属于类型,List<dynamic>
但您正在接受响应,Map String, dynamic
但是您可以执行以下操作
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:clickmeetplay/iam/user/postbean.dart';
import 'package:http/http.dart' as http;
class PostHome extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(home: Scaffold(body: PostScreen(),),);
}
}
class PostScreen extends StatefulWidget {
@override
_PostScreenState createState() => _PostScreenState();
}
class _PostScreenState extends State<PostScreen> {
List<Post> _postList =new List<Post>();
Future<List<Post> > fetchPost() async {
final response =
await http.get('http://alkadhum-col.edu.iq/wp-json/wp/v2/posts/');
if (response.statusCode == 200) {
// If the call to the server was successful, parse the JSON
List<dynamic> values=new List<dynamic>();
values = json.decode(response.body);
if(values.length>0){
for(int i=0;i<values.length;i++){
if(values[i]!=null){
Map<String,dynamic> map=values[i];
_postList .add(Post.fromJson(map));
debugPrint('Id-------${map['id']}');
}
}
}
return _postList;
} else {
// If that call was not successful, throw an error.
throw Exception('Failed to load post');
}
}
@override
Widget build(BuildContext context) {
return Container();
}
@override
void initState() {
fetchPost();
}
}
豆类
class Post {
final int id;
String title;
String link;
Post({this.id, this.title, this.link});
factory Post.fromJson(Map<String, dynamic> json) {
return Post(
id: json['id'],
title: json['title'].toString(),
link: json['link'].toString()
);
}
}
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我来说两句