the flutter document show a demo for SliverAppBar
+ TabBar
+ TabBarView with ListView
use NestedScrollView
, and it's a bit complex, so I wonder is there a simply and clear way to implement it. I tried this:
CustomScrollView
slivers:
SliverAPPBar
bottom: TabBar
TabBarView
children: MyWidget(list or plain widget)
got error:
flutter: The following assertion was thrown building Scrollable(axisDirection: right, physics:
flutter: A RenderViewport expected a child of type RenderSliver but received a child of type _RenderExcludableScrollSemantics.
flutter: RenderObjects expect specific types of children because they coordinate with their children during layout and paint. For example, a RenderSliver cannot be the child of a RenderBox because a RenderSliver does not understand the RenderBox layout protocol.
and
flutter: Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 3497 pos 14: 'owner._debugCurrentBuildTarget == this': is not true.
HERE IS MY CODE:
import 'package:flutter/material.dart';
main(List<String> args) {
runApp(MyScrollTabListApp());
}
class MyScrollTabListApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(title: "aa", home: MyScrollTabListHomePage());
}
}
class MyScrollTabListHomePage extends StatefulWidget {
@override
MyScrollTabListHomePageState createState() {
return new MyScrollTabListHomePageState();
}
}
class MyScrollTabListHomePageState extends State<MyScrollTabListHomePage>
with SingleTickerProviderStateMixin {
final int _listItemCount = 300;
final int _tabCount = 8;
TabController _tabController;
@override
void initState() {
_tabController = TabController(length: _tabCount, vsync: this);
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
expandedHeight: 240.0,
title: Text("Title"),
pinned: true,
bottom: TabBar(
controller: _tabController,
isScrollable: true,
tabs: List<Tab>.generate(_tabCount, (int i) {
return Tab(text: "TAB$i");
}),
),
),
TabBarView(
controller: _tabController,
children: List<Widget>.generate(_tabCount, (int i) {
return Text('line $i');
}),
),
],
),
);
}
}
and for the official demo, it use struct like this
DefaultTabController
NestedScrollView
headerSliverBuilder
SliverOverlapAbsorber
handle
SliverAppBar
TabBarView
CustomScrollView
SliverOverlapInjector
handle
SliverPadding
Use NestedScrollView
, here is the working code.
@override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder: (context, value) {
return [
SliverAppBar(
bottom: TabBar(
tabs: [
Tab(icon: Icon(Icons.call), text: "Call"),
Tab(icon: Icon(Icons.message), text: "Message"),
],
),
),
];
},
body: TabBarView(
children: [
CallPage(),
MessagePage(),
],
),
),
),
);
}