如何在FutureBuilder中使用SliverList
如何在FutureBuilder中使用SliverList
提问于 2018-09-03 09:27:20
我想把ListView转换成CustomScrollView，所以我需要把FutureBuilder转换成SliverList。
这里是我的代码：
class LatestNewsList extends StatefulWidget {
@override
_LatestNewsListState createState() => _LatestNewsListState();
}
class _LatestNewsListState extends State<LatestNewsList> {
@override
Widget build(BuildContext context) {
return FutureBuilder<List<Data>>(
future: getQuake(),
builder: (context, snapshot){
if(snapshot.hasError) print(snapshot.error);
return snapshot.hasData
? NewsList(latestNews: snapshot.data,)
: Center(child: CircularProgressIndicator());
},
);
}
}
class NewsList extends StatelessWidget {
final List<Data> latestNews;
NewsList({this.latestNews});
@override
Widget build(BuildContext context) {
return new ListView.builder(
itemCount: latestNews.length,
itemBuilder: (context, index){
return new GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => Browser(url: latestNews[index].post_link,)
)
);
},
child: new LatestNewsItem(
post_title: latestNews[index].post_title,
post_link: latestNews[index].post_link,
img_src: latestNews[index].img_src,
),
);
}
);
}
}如何将相同的FutureBuilder逻辑转换为SliverList?
回答 2
Stack Overflow用户
回答已采纳
发布于 2018-09-03 12:01:30
CustomScrollView的子级必须是条，不能使用FutureBuilder。
相反，当未来完成时，重新构建CustomScrollView：
// build fixed items outside of the FutureBuilder for efficiency
final someOtherSliver = SliverToBoxAdapter(...);
return FutureBuilder<List<Data>>(
future: getQuake(), // this is a code smell. Make sure that the future is NOT recreated when build is called. Create the future in initState instead.
builder: (context, snapshot){
Widget newsListSliver;
if(snapshot.hasData) {
newsListSliver = SliverList(delegate: SliverChildBuilderDelegate(...))
} else {
newsListSliver = SliverToBoxAdapter(child: CircularProgressIndicator(),);
}
return CustomScrollView(
slivers: <Widget>[
someOtherSliver,
newsListSliver
],
);
},
);如果您有多个依赖于Futures或Streams的条条，则可以链接构建器：
return FutureBuilder<..>(
...
builder: (context, snapshot1) {
return FutureBuilder<..>(
...
builder: (context, snapshot2) {
return CustomScrollView(...);
}
)
}
)Stack Overflow用户
发布于 2019-05-16 07:39:48
使用SliverFillRemaining
Widget build(BuildContext context) {
return new Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverFillRemaining(
child: FutureBuilder(
future: getData(),
builder: (context, snapshot) {
if (snapshot.data == null)
return new Container(
child: Center(child: new CircularProgressIndicator()),
);
else
return Text(snapshot.data.name);
},
),
)
],
)
);或者使用SliverList
Widget build(BuildContext context) {
return new Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverList(
delegate: SliverChildListDelegate([Container(
child: FutureBuilder(
future : getData(),
builder: (C,snap){
//do whatever you want
}
)
)]),
)
]
)
)
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/52146850
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