将烧瓶api中的json数据解析为flutter列表

Question

我正在使用Flutter&Flask api。我必须从flask api中获取数据，并迅速保存到列表中。我是Flutter的初学者，所以请耐心等待！

以下是我迄今为止所做的：

import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
List<String> images = [
"assets/image_04.jpg",
"assets/image_03.jpg",
"assets/image_02.jpg",
"assets/image_06.jpg",
];
List<String> title = [];
class Ayah {
final String text;
final String translation;
final String sound;
final String ref;
Ayah({this.text, this.translation, this.sound, this.ref});
factory Ayah.fromJson(Map<String, dynamic> json) {
return Ayah(
text: json['text'],
translation: json['translation'],
sound: json['sound'],
ref: json['ref']);
}
}
// A function that converts a response body into a List<Photo>.
List<Ayah> parseAyahs(String responseBody) {
final parsed = json.decode(responseBody).cast<Map<String, dynamic>>();
List<Ayah> mylist = parsed.map<Ayah>((json) => Ayah.fromJson(json)).toList();
print('this is here:');
for (int i = 0; i < parsed.length; i++) {
print(parsed[i]);
title.add(parsed[i]['ref']);
}
return mylist;
}
Future<List<Ayah>> fetchAyahs(http.Client client) async {
final response =
await client.get('https://jsonplaceholder.typicode.com/photos');
// return compute(parseAyahs, response.body);
return parseAyahs(response.body);
}

这是Widget，我想在其中使用这些数据：

class CardScrollWidget extends StatelessWidget {
var currentPage;
var padding = 20.0;
var verticalInset = 20.0;
CardScrollWidget(this.currentPage);
@override
Widget build(BuildContext context) {
return new AspectRatio(
aspectRatio: widgetAspectRatio,
child: LayoutBuilder(builder: (context, contraints) {
var width = contraints.maxWidth;
var height = contraints.maxHeight;
var safeWidth = width - 2 * padding;
var safeHeight = height - 2 * padding;
var heightOfPrimaryCard = safeHeight;
var widthOfPrimaryCard = heightOfPrimaryCard * cardAspectRatio;
var primaryCardLeft = safeWidth - widthOfPrimaryCard;
var horizontalInset = primaryCardLeft / 2;
List<Widget> cardList = new List();
for (var i = 0; i < images.length; i++) {
var delta = i - currentPage;
bool isOnRight = delta > 0;
var start = padding +
max(
primaryCardLeft -
horizontalInset * -delta * (isOnRight ? 15 : 1),
0.0);
var cardItem = Positioned.directional(
top: padding + verticalInset * max(-delta, 0.0),
bottom: padding + verticalInset * max(-delta, 0.0),
start: start,
textDirection: TextDirection.rtl,
child: ClipRRect(
borderRadius: BorderRadius.circular(16.0),
child: Container(
decoration: BoxDecoration(color: Colors.white, boxShadow: [
BoxShadow(
color: Colors.black12,
offset: Offset(3.0, 6.0),
blurRadius: 10.0)
]),
child: AspectRatio(
aspectRatio: cardAspectRatio,
child: Stack(
fit: StackFit.expand,
children: <Widget>[
Image.asset(images[i], fit: BoxFit.cover),
Align(
alignment: Alignment.bottomLeft,
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Padding(
// padding: EdgeInsets.symmetric(
//     horizontal: 16.0, vertical: 18.0),
padding: const EdgeInsets.only(
bottom: 60, left: 20, right: 8),
child: Text(title[i],
style: TextStyle(
color: Colors.white,
fontSize: 25.0,
fontFamily: "SF-Pro-Text-Regular")),
),
SizedBox(
height: 20.0,
),
Padding(
padding: const EdgeInsets.only(
left: 22.0, bottom: 72.0),
child: Container(
padding: EdgeInsets.symmetric(
horizontal: 22.0, vertical: 6.0),
decoration: BoxDecoration(
color: Colors.blueAccent,
borderRadius: BorderRadius.circular(20.0)),
child: Text("Read Later",
style: TextStyle(color: Colors.white)),
),
)
],
),
)
],
),
),
),
),
);
cardList.add(cardItem);
}
return Stack(
children: cardList,
);
}),
);
}
}

我无法将数据输入title列表。JSON响应在一个数组中有5个JSON对象。

Answer 1

我的场景

我也有类似的要求，Flutter应用程序需要从烧瓶后端获取数据。

1. 后端正在本地计算机中运行
2. Flutter应用程序在外部移动应用程序中运行

主要想法

• 如果我们想从连接到局域网的其他计算机或设备向我们的API发出HTTP请求，我们应该使用开发计算机IP地址0.0.0.0(对于IPv4配置(或：：(对于IPv6配置(作为我们的开发服务器所需的IP地址
• 如果我们将0.0.0.0指定为IPv4配置所需的IP地址，那么开发服务器将侦听端口5000上的每个接口

步骤

1. 因此，在flask后端为调用app.run添加一个host参数

if __name__ == '__main__': 
app.run(host='0.0.0.0', debug=True)

2. 现在本地网络中的所有设备都可以使用计算机的本地IP访问它。例如：192.168.1.101

您可以在Windows上使用ipconfig或在Linux/Mac 上使用ifconfig检查本地IP

3. 以下是Flutter端的get调用示例

class MovieApiService {
static List<Movie> parseProducts(String responseBody) {
final parsed = json.decode(responseBody);
print(parsed);
return parsed.map<Movie>((json) =>Movie.fromJson(json)).toList();
}
static Future<List<Movie>> getMovies() async {
final response = await http.get('http://192.168.1.101:5000/movies');
if (response.statusCode == 200) {
return parseProducts(response.body);
} else {
return null;
}
}
}

更多参考：https://subscription.packtpub.com/book/application_development/9781789532227/1/ch01lvl1sec23/making-http-requests-to-the-flask-api

https://www.tutorialspoint.com/flutter/flutter_accessing_rest_api.htm