我正在尝试为 SliverAppBar()
中的每个主选项卡(嵌套选项卡栏)显示选项卡.它看起来像这样:
See the image
See the GIF
考试标签的内容在 Container()
小部件(图像中的错误来自)。
现在,有了 Container()
小部件 SliverAppBar()
当用户滚动检查选项卡内容(图像中的白屏)时会崩溃,现在一切正常。
所以,在我更换了 Container()
之后与 ListView.builder()
使选项卡内容可滚动,现在我无法折叠 SliverAppBar()
从选项卡内容(图像中的白屏)。但我可以从SliverAppBar()
.
See this GIF after I added ListView.builder()
那么,如何使用 Listview 使 SliverAppBar 可滚动(折叠)?
可以任何人帮助 我?请 :(
这个例子(演示):
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(title: 'SliverAppBar App Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder:
(BuildContext context, bool innerBoxIsScrolled) {
return [
SliverOverlapAbsorber(
handle:
NestedScrollView.sliverOverlapAbsorberHandleFor(context),
child: SliverSafeArea(
top: false,
sliver: SliverAppBar(
pinned: true,
title: Text(widget.title),
expandedHeight: 500,
),
),
),
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(tabs: [Tab(text: 'Tab A'), Tab(text: 'Tab B')]),
Colors.blue,
),
pinned: false,
),
];
},
body: TabBarView(
children: <Widget>[
NestedTabs('A'),
NestedTabs('B'),
],
),
),
),
),
);
}
}
// This class is to handle the main tabs (Tab A & Tab B)
class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
_SliverAppBarDelegate(this._tabBar, this._color);
TabBar _tabBar;
final Color _color;
@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(
color: _color,
alignment: Alignment.center,
child: _tabBar,
);
}
@override
bool shouldRebuild(_SliverAppBarDelegate oldDelegate) {
return false;
}
}
class NestedTabs extends StatelessWidget {
final String mainTabName;
NestedTabs(this.mainTabName);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size.fromHeight(20),
child: Container(
color: Colors.blue,
alignment: Alignment.bottomCenter,
child: TabBar(
tabs: [
Tab(text: 'Tab $mainTabName-1'),
Tab(text: 'Tab $mainTabName-2')
],
),
),
),
body: TabBarView(
children: [
ListView.builder(
padding: const EdgeInsets.all(8),
itemCount: 500,
itemBuilder: (BuildContext context, int index) {
return Container(
height: 50,
width: 200,
color: Colors.black45,
child: Center(child: Text('Index ${index}')));
},
),
ListView.builder(
padding: const EdgeInsets.all(8),
itemCount: 500,
itemBuilder: (BuildContext context, int index) {
return Container(
height: 50,
width: 200,
color: Colors.black45,
child: Center(child: Text('Index ${index}')));
},
)
],
),
);
}
}
谢谢 :)
最佳答案
对 ListView 使用 SliverList() 而不是 SliverFillRemaining
关于flutter - SliverAppBar() 不会与 Flutter 中的 ListView 折叠,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59778387/