在我的 Flutter 应用程序中，我试图实现一个从集合listview中获取数据作为流的方法。Firestore大部分都按预期工作-我可以将Firestore文档详细信息推送到下一页（详细信息页面），但是在返回主页时，应用程序不记得列表视图的位置-可能是因为它是一个流？
我需要您的帮助和意见来帮助我实现目标吗？以下是供参考的代码：
试过了AutomaticKeepAliveClientMixin；仍然没有得到预期的结果。
我期待在有状态的小部件中实现密钥来管理状态
Widget build(BuildContext context) {
ListTile makeListTile(DocumentSnapshot document) => ListTile(
contentPadding:
EdgeInsets.symmetric(horizontal: 20.0, vertical: 10.0),
leading: Container(
padding: EdgeInsets.only(right: 12.0),
decoration: new BoxDecoration(
border: new Border(
right: new BorderSide(width: 1.0, color: Colors.white24))),
child: Icon(Icons.notifications_active, color: Colors.white),
),
title: Text(
document['title'],
style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold),
),
subtitle: Text(document['shortDesc'].toString(),
style: TextStyle(color: Colors.white)),
trailing:
Icon(Icons.keyboard_arrow_right, color: Colors.white, size: 30.0),
onTap: () {
Navigator.of(context).push(new MaterialPageRoute(
builder: (context) => NewsDetails(document: document)));
},
);
final topAppBar = AppBar(
elevation: 0.1,
backgroundColor: Colors.teal,
title: Text('FirestoreDemo'),
centerTitle: true,
);
Card makeCard(DocumentSnapshot document) => Card(
elevation: 8.0,
margin: new EdgeInsets.symmetric(horizontal: 10.0, vertical: 6.0),
child: Container(
decoration: BoxDecoration(color: Colors.teal),
child: makeListTile(document),
),
);
Card makeUnreadCard(DocumentSnapshot document) => Card(
elevation: 8.0,
margin: new EdgeInsets.symmetric(horizontal: 10.0, vertical: 6.0),
child: Container(
decoration: BoxDecoration(color: Colors.deepOrangeAccent),
child: makeListTile(document),
),
);
return new Scaffold(
appBar: topAppBar,
drawer: new MainDrawer(labels: widget.labels),
body: new StreamBuilder<QuerySnapshot>(
stream: Firestore.instance
.collection('collecton01')
.orderBy('date', descending: true)
.snapshots(),
builder:
(BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (!snapshot.hasData)
return Center(child: CircularProgressIndicator(),);
if (snapshot.hasError) return Center (child:new Text('Error: ${snapshot.error}'));
final int itemsCount = snapshot.data.documents.length;
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return new CircularProgressIndicator();
default:
return new ListView.builder(
scrollDirection: Axis.vertical,
controller: _scrollController,
shrinkWrap: true,
itemCount: itemsCount,
itemBuilder: (BuildContext context, int index) {
final DocumentSnapshot document =
snapshot.data.documents[index];
if (document['color'] == true) {
return makeUnreadCard(snapshot.data.documents[index]);
}
return makeCard(snapshot.data.documents[index]);
},
);
}
}),
);