例如,类似于个人资料页面中的Instagram
,我想在滚动视图时将Tabbar
固定在屏幕顶部,例如:
我认为我应该用SliverAppBar
实现它,这是我的代码,但是它不能正常工作,并且制表符元素的顶部将更改高度
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
with SingleTickerProviderStateMixin {
TabController _tabController;
ScrollController _scrollViewController;
@override
void initState() {
super.initState();
_tabController = TabController(vsync: this, length: 2);
_scrollViewController = ScrollController(initialScrollOffset: 0.0);
}
@override
void dispose() {
_tabController.dispose();
_scrollViewController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
controller: _scrollViewController,
headerSliverBuilder: (BuildContext context, bool boxIsScrolled) {
return <Widget>[
SliverAppBar(
title: Column(
children: <Widget>[
Container(
height: 200.0,
color: Colors.green,
),
Container(
height: 200.0,
color: Colors.yellow,
),
],
),
pinned: true,
floating: true,
forceElevated: boxIsScrolled,
bottom: TabBar(
tabs: <Widget>[
Tab(
text: "Home",
icon: Icon(Icons.home),
),
Tab(
text: "Example page",
icon: Icon(Icons.help),
)
],
controller: _tabController,
),
)
];
},
body: TabBarView(
children: <Widget>[
PageOne(),
PageTwo(),
],
controller: _tabController,
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.control_point),
onPressed: () {
_tabController.animateTo(1,
curve: Curves.bounceInOut, duration: Duration(milliseconds: 10));
// _scrollViewController.animateTo(
// _scrollViewController.position.minScrollExtent,
// duration: Duration(milliseconds: 1000),
// curve: Curves.decelerate);
_scrollViewController
.jumpTo(_scrollViewController.position.maxScrollExtent);
},
),
);
}
}
class PageOne extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Image.asset(
'assets/photos/wallpaper-1.jpg',
width: 200.0,
),
Image.asset(
'assets/photos/wallpaper-2.jpg',
width: 200.0,
),
Image.asset(
'assets/photos/wallpaper-3.jpg',
width: 200.0,
),
],
),
);
}
}
class PageTwo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return ListView.builder(
itemExtent: 250.0,
itemBuilder: (context, index) => Container(
padding: EdgeInsets.all(10.0),
child: Material(
elevation: 4.0,
borderRadius: BorderRadius.circular(5.0),
color: index % 2 == 0 ? Colors.cyan : Colors.deepOrange,
child: Center(
child: Text(index.toString()),
),
),
),
);
}
}
这对您有用吗?
import 'package:flutter/material.dart';
class Popo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[100],
body: SafeArea(
child: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
backgroundColor: Colors.grey[100],
title: Container(
color: Colors.grey[100],
height: 200,
width: MediaQuery.of(context).size.width,
child: Center(
child: Text(
"Head",
style: TextStyle(
color: Colors.black
),
),
),
),
),
SliverAppBar(
pinned: true,
backgroundColor: Colors.white,
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Icon(
Icons.dashboard
),
Icon(
Icons.tv
),
Icon(
Icons.person
),
],
),
),
SliverAnimatedList(
itemBuilder: (_, index, ___){
return ListTile(
title: Text(index.toString()),
);
},
initialItemCount: 100,
)
],
),
),
);
}
}
输出: