我正在尝试从互联网获取数据。这是json字符串:
{"channel":{"id":1090161,"name":"İscaklik","description":"İscakliği okeyrum da.","latitude":"0.0","longitude":"0.0","field1":"nem","field2":"iscaklik","created_at":"2020-06-27T11:56:47Z","updated_at":"2020-06-27T11:56:47Z","last_entry_id":1},"feeds":[{"created_at":"2020-06-27T12:02:32Z","entry_id":1,"field1":"5"}]}
我想在“提要”中获取“field1”。我的代码是这样的:
class _DataState extends State<Data> {
Future<String> AlbumState;
void initState() {
super.initState();
oku();
}
var a;
Future<List<Post>> oku() async {
final response = await http.get(
'https://api.thingspeak.com/channels/1090161/fields/1.json?api_key=JD9JYHAT2YHOI5Q3&results=1');
if (response.statusCode == 200) {
var responseJson = json.decode(response.body);
return (responseJson['feeds'] as List)
.map((p) => Post.fromJson(p))
.toList();
} else {
throw Exception('La bulamadık la böyle bi şey yoh la');
}
}
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Fetch Data Example',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
body: Center(
child: FutureBuilder<List<Post>>(
future: oku(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text(snapshot.data.toString());
} else if (snapshot.hasError) {
return Text("${snapshot.error}");
}
return CircularProgressIndicator();
},
),
),
),
);
}
}
class Post {
final String field1;
Post({this.field1});
factory Post.fromJson(Map<String, dynamic> json) {
return new Post(
field1: json['entry_id'].toString(),
);
}
}
结果如下:我想看5.(哪个是feed的field1)
为什么我看到这个?
我怎样才能解决这个问题?
最佳答案
因为您尝试使用整个对象,例如“文本”小部件中的“字符串”。尝试调用Post类中的field1
属性。
return Text(snapshot.data[0].field1);
关于json - 为什么我的json代码给出了Post实例,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/62613403/