如何在flutter中每隔x秒从api获取数据？

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

class DataFetcher extends StatefulWidget {
  @override
  _DataFetcherState createState() => _DataFetcherState();
}

class _DataFetcherState extends State<DataFetcher> {
  Timer _timer;
  List<dynamic> _data = [];

  @override
  void initState() {
    super.initState();
    // 开始定时器，每隔 x 秒执行一次获取数据的方法
    _timer = Timer.periodic(Duration(seconds: x), (Timer timer) {
      _getDataFromApi();
    });
  }

  @override
  void dispose() {
    // 取消定时器
    _timer.cancel();
    super.dispose();
  }

  Future<void> _getDataFromApi() async {
    try {
      // 发送 HTTP 请求获取数据
      final response = await http.get(Uri.parse('API_URL'));
      if (response.statusCode == 200) {
        // 解析 JSON 数据
        final jsonData = json.decode(response.body);
        setState(() {
          _data = jsonData;
        });
      } else {
        throw Exception('Failed to fetch data');
      }
    } catch (error) {
      print(error);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Data Fetcher'),
      ),
      body: ListView.builder(
        itemCount: _data.length,
        itemBuilder: (BuildContext context, int index) {
          return ListTile(
            title: Text(_data[index]['title']),
            subtitle: Text(_data[index]['description']),
          );
        },
      ),
    );
  }
}