如何访问 Json 数据

Question

我有一些 Json 数据。但是如果不写第一个键名我就无法访问它的内部。 Json 数据的 link 是 https://api.genelpara.com/embed/borsa.json 我想把它们放到 Listview 中。我该如何放置它们？如果我像代码一样编写，我只能访问 'satis' 键和值并在 Listview 上显示，但我想访问 'ALGYO' 键作为值并在 Listview 上显示。

child: Center(child: Text(' ${snapshot.data['ALGYO']['satis']}'))

Answer 1

您需要从您的 JSON 中获取 keys（例如 ALGYO 和 ARZUM），然后您可以访问其中的数据。试试下面的代码，你可以轻松地在你想要的地方添加alis和degisim：

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'ListView',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  final data = {
    'ALGYO': {'satis': "20.18", 'alis': "20.16", 'degisim': "-1,46"},
    'ARZUM': {'satis': "17.68", 'alis': "17.68", 'degisim': "-20,93"},
    'ACSEL': {'satis': "16.41", 'alis': "16.41", 'degisim': "-2,32"},
    'ADANA': {'satis': "12.19", 'alis': "12.19", 'degisim': "0,00"},
    'ADBGR': {'satis': "8.62", 'alis': "8.62", 'degisim': "0,00"},
    'ADEL': {'satis': "0.0476", 'alis': "0.0476", 'degisim': "-1,04"},
    'ADESE': {'satis': "1.2", 'alis': "1.2", 'degisim': "-1,64"},
    'ADNAC': {'satis': "2.09", 'alis': "2.09", 'degisim': "0,00"},
    'AEFES': {'satis': "21.46", 'alis': "21.46", 'degisim': "-1,29"},
    'AFYON': {'satis': "3.63", 'alis': "3.63", 'degisim': "-0,82"},
  };

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ListView'),
      ),
      body: ListView.builder(
        itemCount: data.length,
        itemBuilder: (BuildContext context, int index) {
          // this will be the key for the current item
          String key = data.keys.elementAt(index);
          // here you can see how to access "satis" under
          // current key
          return ListTile(
              title: Text("$key"), subtitle: Text(data[key]!["satis"]!));
        },
      ),
    );
  }
}

如何访问 Json 数据

How to access Json data's

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flutter-listview