您必须将状态（收藏夹与否）存储在父窗口小部件中。该
ListView.builder部件上创建和需求破坏的项目，并且状态
时，该项目被破坏被丢弃。这意味着列表项应该始终是无状态的小部件。
class Item { Item({this.name, this.isFavorite}); String name; bool isFavorite;}class MyList extends StatefulWidget { @override State<StatefulWidget> createState() => MyListState();}class MyListState extends State<MyList> { List<Item> items; @override void initState() { super.initState(); // Generate example items items = List<Item>(); for (int i = 0; i < 100; i++) { items.add(Item( name: 'Item $i', isFavorite: false, )); } } @override Widget build(BuildContext context) { return ListView.builder( itemCount: items.length, itemBuilder: (context, index) { return ListItem( items[index], () => onFavoritePressed(index), ); }, ); } onFavoritePressed(int index) { final item = items[index]; setState(() { item.isFavorite = !item.isFavorite; }); }}class ListItem extends StatelessWidget { ListItem(this.item, this.onFavoritePressed); final Item item; final VoidCallback onFavoritePressed; @override Widget build(BuildContext context) { return ListTile( title: Text(item.name), leading: IconButton( icon: Icon(item.isFavorite ? Icons.favorite : Icons.favorite_border), onPressed: onFavoritePressed, ), ); }}
