我一直在尝试找到一种方法,如何通过在 Flutter 中使用 http 请求从某个服务器获取项目。
所以我添加并编辑了一些我发现的代码,但我一直无法使用它。
这是下面的代码。
import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
Future<Post> fetchPost() async {
var params = {
"citycode": Uri.encodeFull("25"),
"nodeId": Uri.encodeFull("DJB8001793ND"),
};
Uri uri = Uri.parse('http://openapi.tago.go.kr/openapi/service/ArvlInfoInqireService/getSttnAcctoArvlPrearngeInfoList');
final newURI = uri.replace(queryParameters: params);
final response = await http.get(
newURI,
headers: {HttpHeaders.authorizationHeader: "t8iGBTBFQc5nMq9ytuMZQ7jxR8ZMzohG%2F5o0i80f%2BehjFhMpkADfArAvFk%2BjHsPMFFEThQgejzujdpfou%2FDWng%3D%3D"},
);
/*
final responseJson = json.decode(response.body);
print('$responseJson');
return Post.fromJson(responseJson);
*/
if (response.statusCode == 200) {
// If server returns an OK response, parse the JSON.
return Post.fromJson(json.decode(response.body));
} else {
// If that response was not OK, throw an error.
throw Exception('Failed to load post');
}
}
class Post {
final String nodeid;
final String nodenm;
final int arrtime;
final int routeno;
Post({this.nodeid, this.nodenm, this.arrtime, this.routeno});
factory Post.fromJson(Map<String, dynamic> json) {
return Post(
nodeid: json['nodeid'],
nodenm: json['nodenm'],
arrtime: json['arrtime'],
routeno: json['routeno'],
);
}
}
void main() => runApp(MyApp(post: fetchPost()));
class MyApp extends StatelessWidget {
final Future<Post> post;
MyApp({Key key, this.post}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Fetch Data Example',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
appBar: AppBar(
title: Text('Fetch Data Example'),
),
body: Center(
child: FutureBuilder<Post>(
future: post,
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text(snapshot.data.nodenm);
} else if (snapshot.hasError) {
return Text("${snapshot.error}");
}
// By default, show a loading spinner.
return CircularProgressIndicator();
},
),
),
),
);
}
}
我收到这个错误,它是由下面的这段代码引起的。 我认为原因是我未能获得数据..但我不知道为什么。
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text(snapshot.data.nodenm);
} else if (snapshot.hasError) {
return Text("${snapshot.error}");
}
最佳答案
服务器正在向您返回 XML,但您正试图将其作为 JSON 进行解析。
您应该尝试向您的请求添加一个 Accept
header ,并让服务器返回给您 JSON 数据,而不是 XML:
headers: {HttpHeaders.authorizationHeader: "...", "Accept": "application/json"},
关于flutter - http请求不断失败,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56965085/