假设我有这样的事情:
return FutureBuilder(
future: _loadingDeals,
builder: (BuildContext context, AsyncSnapshot snapshot) {
return RefreshIndicator(
onRefresh: _handleRefresh,
...
)
}
)
在 _handleRefresh
方法中,我想以编程方式触发 FutureBuilder 的重新运行。
有这种事吗?
用例:
当用户拉下 refreshIndicator
时,_handleRefresh
只会让 FutureBuilder
重新运行。
编辑:
完整的代码片段端到端,没有刷新部分。我已经切换到使用 StreamBuilder
,refreshIndicator
部分如何适应所有这些?
class DealList extends StatefulWidget {
@override
State<StatefulWidget> createState() => new _DealList();
}
class _DealList extends State<DealList> with AutomaticKeepAliveClientMixin {
// prevents refreshing of tab when switch to
// Why? https://stackoverflow.com/q/51224420/1757321
bool get wantKeepAlive => true;
final RestDatasource api = new RestDatasource();
String token;
StreamController _dealsController;
@override
void initState() {
super.initState();
_dealsController = new StreamController();
_loadingDeals();
}
_loadingDeals() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
this.token = prefs.getString('token');
final res =
this.api.checkInterests(this.token).then((interestResponse) async {
_dealsController.add(interestResponse);
return interestResponse;
});
return res;
}
_handleRefresh(data) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = prefs.getString('token');
await this.api.checkInterests(token).then((interestResponse) {
_dealsController.add(interestResponse);
});
return null;
}
@override
Widget build(BuildContext context) {
super.build(context); // <-- this is with the wantKeepAlive thing
return StreamBuilder(
stream: _dealsController.stream,
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasError) {
...
}
if (snapshot.connectionState != ConnectionState.done) {
return Center(
child: CircularProgressIndicator(),
);
}
if (!snapshot.hasData &&
snapshot.connectionState == ConnectionState.done) {
return Text('No deals');
}
if (snapshot.hasData) {
return ListView.builder(
physics: const AlwaysScrollableScrollPhysics(),
itemCount: snapshot.data['deals'].length,
itemBuilder: (context, index) {
final Map deal = snapshot.data['deals'][index];
return ListTile(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => DealsDetailPage(
dealDetail: deal,
),
),
);
},
title: Text(deal['name']),
subtitle: Text(deal['expires']),
);
},
),
}
},
);
}
}
最佳答案
为什么不使用 StreamBuilder 和 Stream 而不是 FutureBuilder?
类似的...
class _YourWidgetState extends State<YourWidget> {
StreamController<String> _refreshController;
...
initState() {
super...
_refreshController = new StreamController<String>();
_loadingDeals();
}
_loadingDeals() {
_refreshController.add("");
}
_handleRefresh(data) {
if (x) _refreshController.add("");
}
...
build(context) {
...
return StreamBuilder(
stream: _refreshController.stream,
builder: (BuildContext context, AsyncSnapshot snapshot) {
return RefreshIndicator(
onRefresh: _handleRefresh(snapshot.data),
...
)
}
);
}
}
我使用 StreamBuilder 创建了一个带有 Flutter 主要示例的 Gist,check it out
关于dart - Flutter 以编程方式触发 FutureBuilder,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51663378/