这应该可以解决您的问题。基本上，您始终希望在
build方法层次结构中创建Widget 。
import 'dart:async';import 'package:flutter/material.dart';void main() => runApp(new MaterialApp(home: new Scaffold(body: new MainWidget())));class MainWidget extends StatefulWidget { @override State createState() => new MainWidgetState();}class MainWidgetState extends State<MainWidget> { List<ItemData> _data = new List(); Timer timer; Widget build(BuildContext context) { return new ListView(children: _data.map((item) => new ChildWidget(item)).toList()); } @override void initState() { super.initState(); timer = new Timer.periodic(new Duration(seconds: 2), (Timer timer) async { ItemData data = await loadData(); this.setState(() { _data = <ItemData>[data]; }); }); } @override void dispose() { super.dispose(); timer.cancel(); } static int testCount = 0; Future<ItemData> loadData() async { testCount++; return new ItemData("Testing #$testCount"); }}class ChildWidget extends StatefulWidget { ItemData _data; ChildWidget(ItemData data) { _data = data; } @override State<ChildWidget> createState() => new ChildState();}class ChildState extends State<ChildWidget> { @override Widget build(BuildContext context) { return new GestureDetector(onTap: () => foo(), child: new Padding( padding: const EdgeInsets.symmetric(vertical: 12.0, horizontal: 24.0), child: new Card( child: new Container( padding: const EdgeInsets.all(8.0), child: new Text(widget._data.title), ), ), ) ); } foo() { print("Card Tapped: " + widget._data.toString()); }}class ItemData { final String title; ItemData(this.title); @override String toString() { return 'ItemData{title: $title}'; }}
