如何在Flutter中更新网络图像

dependencies:
  flutter:
    sdk: flutter
  http: ^0.13.4
  cached_network_image: ^3.1.0

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

class NetworkImagePage extends StatefulWidget {
  @override
  _NetworkImagePageState createState() => _NetworkImagePageState();
}

class _NetworkImagePageState extends State<NetworkImagePage> {
  String imageUrl = 'https://example.com/image.jpg';

  Future<void> _updateImage() async {
    // 发起HTTP请求获取新的图像URL
    final response = await http.get(Uri.parse('https://example.com/api/getImageUrl'));
    if (response.statusCode == 200) {
      setState(() {
        imageUrl = response.body;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Network Image'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CachedNetworkImage(
              imageUrl: imageUrl,
              placeholder: (context, url) => CircularProgressIndicator(),
              errorWidget: (context, url, error) => Icon(Icons.error),
            ),
            ElevatedButton(
              onPressed: _updateImage,
              child: Text('Update Image'),
            ),
          ],
        ),
      ),
    );
  }
}