我是 Flutter 新手,我尝试从“10.0.2.2:8000/api/members”上的 api 获取数据,但收到错误,例如类型列表动态不是类型“列表”的子类型。
我正在遵循颤动的示例:https://flutter.dev/docs/cookbook/networking/fetch-data#complete-example https://flutter.dev/docs/cookbook/networking/fetch-data#complete-example
请帮助我遵循有用的教程并告诉我如何修复此代码。
我的主页.dart
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:http/http.dart' as http;
import 'dart:convert';
class MyHomePage extends StatefulWidget {
const MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
static const url = "10.0.2.2:8000/api/membres";
Future<List<Map<String, dynamic>>> _future;
@override
void initState() {
super.initState();
_future = fetch();
}
Future<List<Map<String, dynamic>>> fetch() {
return http
.get("http://10.0.2.2:8000/api/membres")
.then((response) {
return response.statusCode == 200
? response.body
: throw 'Error when getting data';
})
.then((body) => json.decode(body)) //
.then((list) => (list as List).cast<Map<String, dynamic>>());
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Home'),
),
body: RefreshIndicator(
onRefresh: () async {
_future = fetch();
setState(() {});
return _future;
},
child: FutureBuilder<List<Map<String, dynamic>>>(
future: _future,
builder: (context, snapshot) {
if (snapshot.hasError) {
return Center(
child: Container(
constraints: BoxConstraints.expand(),
child: SingleChildScrollView(
physics: AlwaysScrollableScrollPhysics(),
child: Text(snapshot.error.toString()),),),);}
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);}
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) {
final item = snapshot.data[index];
return ListTile(
title: Text(item['nom']),
subtitle: Text(item['prenom']),
);
},
);
},
),
),
);
}
}
我用 Postman 测试了 API,它有效:
And this is the error :
![enter image description here](https://i.stack.imgur.com/kH2rA.png)
在模拟器中: