问题描述
我一直在研究 SliverAppBar、CustomScrollView、NestedScrollView、SliverPersistentHeader 等.我找不到一种方法来构建类似 Instagram 用户个人资料屏幕标题的东西，其中只有标签栏被固定.屏幕主体是一个 TabBarView，每个窗格都有一个可滚动的列表.
I've been investigating SliverAppBar, CustomScrollView, NestedScrollView, SliverPersistentHeader, and more. I cannot find a way to build something like the Instagram user profile screen's header where only the tab bar is pinned. The main body of the screen is a TabBarView and each pane has a scrollable list.
使用SliverAppBar，可以很方便的在底部参数中添加TabBar.但我想在该 TabBar 上方有一个未知/可变高度的额外小部件.当页面滚动时，额外的小部件应该滚动出来，然后 TabBar 是固定在屏幕顶部的.
With SliverAppBar, it is easy to add the TabBar in the bottom parameter. But I want to have an extra widget of unknown/variable height above that TabBar. The extra widget should scroll out of the way when the page is scrolled and and then the TabBar is what is pinned at the top of the screen.
我只能管理标签栏之前的固定内容和固定标签栏.我无法让标题向上滚动并将 TabBar 粘贴在 AppBar 正下方的顶部.
All I could manage was a fixed content before the tab bar and a fixed tab bar. I cannot get the header to scroll up and stick the TabBar at the top just just below the AppBar.
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyApp()));
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 2,
child: Scaffold(
appBar: AppBar(
title: Text("pabloaleko"),
),
body: CustomScrollView(
physics: const BouncingScrollPhysics(),
slivers: <Widget>[
SliverToBoxAdapter(
child: SafeArea(
child: Text("an unknown
amount of content
goes here in the header"),
),
),
SliverToBoxAdapter(
child: TabBar(
tabs: [
Tab(child: Text('Days', style: TextStyle(color: Colors.black))),
Tab(child: Text('Months', style: TextStyle(color: Colors.black))),
],
),
),
SliverFillRemaining(
child: TabBarView(
children: [
ListView(
children: <Widget>[
ListTile(title: Text('Sunday 1')),
ListTile(title: Text('Monday 2')),
ListTile(title: Text('Tuesday 3')),
ListTile(title: Text('Wednesday 4')),
ListTile(title: Text('Thursday 5')),
ListTile(title: Text('Friday 6')),
ListTile(title: Text('Saturday 7')),
ListTile(title: Text('Sunday 8')),
ListTile(title: Text('Monday 9')),
ListTile(title: Text('Tuesday 10')),
ListTile(title: Text('Wednesday 11')),
ListTile(title: Text('Thursday 12')),
ListTile(title: Text('Friday 13')),
ListTile(title: Text('Saturday 14')),
],
),
ListView(
children: <Widget>[
ListTile(title: Text('January')),
ListTile(title: Text('February')),
ListTile(title: Text('March')),
ListTile(title: Text('April')),
ListTile(title: Text('May')),
ListTile(title: Text('June')),
ListTile(title: Text('July')),
ListTile(title: Text('August')),
ListTile(title: Text('September')),
ListTile(title: Text('October')),
ListTile(title: Text('November')),
ListTile(title: Text('December')),
],
),
],
),
),
],
),
),
);
}
}
推荐答案
您可以使用 NestedScrollView 和 Scaffold 来实现此行为.
You can achieve this behaviour using NestedScrollView with Scaffold.
因为我们需要动态构建和滚动 AppBar 和 TabBar 之间的小部件，直到 TabBar 到达 AppBar，使用 Scaffold 的 appBar 属性来构建您的 AppBar 并使用 headerSliverBuilder 构建其他未知的小部件高度.使用 NestedScrollView 的 body 属性来构建标签视图.
As we need the widgets between the AppBar and TabBar to be dynamically built and scrolled until TabBar reaches AppBar, use the appBar property of the Scaffold to build your AppBar and use headerSliverBuilder to build other widgets of unknown heights. Use the body property of NestedScrollView to build your tab views.
这样 headerSliverBuilder 的元素会滚动到 body 到达 AppBar 的底部.
This way the elements of the headerSliverBuilder would scroll away till the body reaches the bottom of the AppBar.
单凭文字可能会让人有些困惑，这里举个例子.
Might be a little confusing to understand with mere words, here is an example for you.
代码:
// InstaProfilePage
class InstaProfilePage extends StatefulWidget {
@override
_InstaProfilePageState createState() => _InstaProfilePageState();
}
class _InstaProfilePageState extends State<InstaProfilePage> {
double get randHeight => Random().nextInt(100).toDouble();
List<Widget> _randomChildren;
// Children with random heights - You can build your widgets of unknown heights here
// I'm just passing the context in case if any widgets built here needs access to context based data like Theme or MediaQuery
List<Widget> _randomHeightWidgets(BuildContext context) {
_randomChildren ??= List.generate(3, (index) {
final height = randHeight.clamp(
50.0,
MediaQuery.of(context).size.width, // simply using MediaQuery to demonstrate usage of context
);
return Container(
color: Colors.primaries[index],
height: height,
child: Text('Random Height Child ${index + 1}'),
);
});
return _randomChildren;
}
@override
Widget build(BuildContext context) {
return Scaffold(
// Persistent AppBar that never scrolls
appBar: AppBar(
title: Text('AppBar'),
elevation: 0.0,
),
body: DefaultTabController(
length: 2,
child: NestedScrollView(
// allows you to build a list of elements that would be scrolled away till the body reached the top
headerSliverBuilder: (context, _) {
return [
SliverList(
delegate: SliverChildListDelegate(
_randomHeightWidgets(context),
),
),
];
},
// You tab view goes here
body: Column(
children: <Widget>[
TabBar(
tabs: [
Tab(text: 'A'),
Tab(text: 'B'),
],
),
Expanded(
child: TabBarView(
children: [
GridView.count(
padding: EdgeInsets.zero,
crossAxisCount: 3,
children: Colors.primaries.map((color) {
return Container(color: color, height: 150.0);
}).toList(),
),
ListView(
padding: EdgeInsets.zero,
children: Colors.primaries.map((color) {
return Container(color: color, height: 150.0);
}).toList(),
)
],
),
),
],
),
),
),
);
}
}
输出:
希望这会有所帮助！
这篇关于Flutter 中的 Instagram 个人资料页眉布局的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！