防止内容在 SliverAppBar 下方滚动
Prevent content from scrolling beneath SliverAppBar
我有一个 Sliver 布局,顶部有一个 SliverAppBar,向下滚动时会折叠。
问题如下:
我的 Sliver 布局的内容在 SliverAppBar 下滚动:(不需要)
相反,我想禁止在我的 SliverAppBar 折叠时进一步滚动。
这应该是您可以向下滚动的最大状态:
代码:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
var scrollController = ScrollController();
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Home());
}
}
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder:
(BuildContext context, bool innerBoxIsScrolled) {
return [
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text("Collapsing Toolbar",
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
)),
background: Image.network(
"https://images.pexels.com/photos/396547/pexels-photo-396547.jpeg?auto=compress&cs=tinysrgb&h=350",
fit: BoxFit.cover,
)),
),
SliverPadding(
padding: new EdgeInsets.all(16.0),
sliver: new SliverList(
delegate: new SliverChildListDelegate([
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
new Tab(icon: new Icon(Icons.info), text: "Tab 1"),
new Tab(
icon: new Icon(Icons.lightbulb_outline),
text: "Tab 2"),
],
),
]),
),
),
];
},
body: Center(
child: Text("Sample text"),
),
),
));
}
}
您需要 SliverPersistentHeader
和 _SliverAppBarDelegate
请参阅下面的完整代码
您可以复制粘贴 运行 完整代码
详情请参考这个https://medium.com/@diegoveloper/flutter-collapsing-toolbar-sliver-app-bar-14b858e87abe
代码片段
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
Tab(icon: Icon(Icons.info), text: "Tab 1"),
Tab(icon: Icon(Icons.lightbulb_outline), text: "Tab 2"),
],
),
),
pinned: true,
),
工作演示
完整代码
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
var scrollController = ScrollController();
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Home());
}
}
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return [
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
snap: false,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text("Collapsing Toolbar",
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
)),
background: Image.network(
"https://images.pexels.com/photos/396547/pexels-photo-396547.jpeg?auto=compress&cs=tinysrgb&h=350",
fit: BoxFit.cover,
)),
),
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
Tab(icon: Icon(Icons.info), text: "Tab 1"),
Tab(icon: Icon(Icons.lightbulb_outline), text: "Tab 2"),
],
),
),
pinned: true,
),
];
},
body: Center(
child: Text("Sample text"),
),
),
));
}
}
class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
_SliverAppBarDelegate(this._tabBar);
final TabBar _tabBar;
@override
double get minExtent => _tabBar.preferredSize.height;
@override
double get maxExtent => _tabBar.preferredSize.height;
@override
Widget build(
BuildContext context, double shrinkOffset, bool overlapsContent) {
return new Container(
child: _tabBar,
);
}
@override
bool shouldRebuild(_SliverAppBarDelegate oldDelegate) {
return false;
}
}
我有一个 Sliver 布局,顶部有一个 SliverAppBar,向下滚动时会折叠。
问题如下:
我的 Sliver 布局的内容在 SliverAppBar 下滚动:(不需要)
相反,我想禁止在我的 SliverAppBar 折叠时进一步滚动。
这应该是您可以向下滚动的最大状态:
代码:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
var scrollController = ScrollController();
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Home());
}
}
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder:
(BuildContext context, bool innerBoxIsScrolled) {
return [
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text("Collapsing Toolbar",
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
)),
background: Image.network(
"https://images.pexels.com/photos/396547/pexels-photo-396547.jpeg?auto=compress&cs=tinysrgb&h=350",
fit: BoxFit.cover,
)),
),
SliverPadding(
padding: new EdgeInsets.all(16.0),
sliver: new SliverList(
delegate: new SliverChildListDelegate([
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
new Tab(icon: new Icon(Icons.info), text: "Tab 1"),
new Tab(
icon: new Icon(Icons.lightbulb_outline),
text: "Tab 2"),
],
),
]),
),
),
];
},
body: Center(
child: Text("Sample text"),
),
),
));
}
}
您需要 SliverPersistentHeader
和 _SliverAppBarDelegate
请参阅下面的完整代码
您可以复制粘贴 运行 完整代码
详情请参考这个https://medium.com/@diegoveloper/flutter-collapsing-toolbar-sliver-app-bar-14b858e87abe
代码片段
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
Tab(icon: Icon(Icons.info), text: "Tab 1"),
Tab(icon: Icon(Icons.lightbulb_outline), text: "Tab 2"),
],
),
),
pinned: true,
),
工作演示
完整代码
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
var scrollController = ScrollController();
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Home());
}
}
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return [
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
snap: false,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text("Collapsing Toolbar",
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
)),
background: Image.network(
"https://images.pexels.com/photos/396547/pexels-photo-396547.jpeg?auto=compress&cs=tinysrgb&h=350",
fit: BoxFit.cover,
)),
),
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(
labelColor: Colors.black87,
unselectedLabelColor: Colors.grey,
tabs: [
Tab(icon: Icon(Icons.info), text: "Tab 1"),
Tab(icon: Icon(Icons.lightbulb_outline), text: "Tab 2"),
],
),
),
pinned: true,
),
];
},
body: Center(
child: Text("Sample text"),
),
),
));
}
}
class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
_SliverAppBarDelegate(this._tabBar);
final TabBar _tabBar;
@override
double get minExtent => _tabBar.preferredSize.height;
@override
double get maxExtent => _tabBar.preferredSize.height;
@override
Widget build(
BuildContext context, double shrinkOffset, bool overlapsContent) {
return new Container(
child: _tabBar,
);
}
@override
bool shouldRebuild(_SliverAppBarDelegate oldDelegate) {
return false;
}
}