Flutter:无法获取json API数据

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('Fetch JSON Data')),
        body: Center(child: FetchDataWidget()),
      ),
    );
  }
}

class FetchDataWidget extends StatefulWidget {
  @override
  _FetchDataWidgetState createState() => _FetchDataWidgetState();
}

class _FetchDataWidgetState extends State<FetchDataWidget> {
  String _data = 'No data fetched yet...';

  @override
  void initState() {
    super.initState();
    fetchData();
  }

  Future<void> fetchData() async {
    try {
      final response = await http.get(Uri.parse('https://api.example.com/data'));
      if (response.statusCode == 200) {
        setState(() {
          _data = jsonDecode(response.body)['key']; // 假设JSON中有'key'字段
        });
      } else {
        setState(() {
          _data = 'Failed to load data';
        });
      }
    } catch (e) {
      setState(() {
        _data = 'Error: $e';
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Text(_data);
  }
}