【发布时间】:2020-04-17 13:48:50
【问题描述】:
我正在尝试使用 TabBar 实现 SliverAppBar。在一个选项卡中,我想放置 SliverGrid,而在另一个选项卡中,我想放置一个 SliverList。获取 SliverAppBar 和 TabBar 的基本代码如下。选项卡内容只是 Text() 元素。我想要的是一个扩展的应用栏,其中包含一个图像和一些其他控件。其下方的标签栏和包含网格/列表等的标签栏。当用户向上滚动时,带有标题的应用栏应固定在顶部,标签栏应固定在其下方
Widget _buildUI(Device data) {
return CustomScrollView(
slivers: <Widget>[
SliverAppBar(
floating: true,
snap: true,
pinned: true,
expandedHeight: 250,
flexibleSpace: FlexibleSpaceBar(
title: Text('Page Title'),
background: Image.network(
'http://img1.mukewang.com/5c18cf540001ac8206000338.jpg',
fit: BoxFit.cover,
),
),
),
SliverPersistentHeader(
// TabBar with a ceiling)
pinned: true,
delegate: StickyTabBarDelegate(
child: TabBar(
labelColor: Colors.black,
controller: this.tabController,
tabs: <Widget>[
Tab(text: 'Tab 1'),
Tab(text: 'Tab 2'),
],
),
),
),
SliverFillRemaining(
// TabBarView, the remaining supplement)
child: TabBarView(
controller: this.tabController,
children: <Widget>[
Center(child: Text('Content of Tab 1')),
Center(child: Text('Content of Tab 2')),
],
),
),
],
);
}
现在,当我尝试添加 SliverGrid 而不是 Text() 元素时,出现以下错误,
SliverFillRemaining(
// TabBarView, the remaining supplement)
child: TabBarView(
controller: this.tabController,
children: <Widget>[
Center(
child: SliverGrid.count(
crossAxisCount: 3,
children:
colorList.map((color) => Container(color: color)).toList(),
)),
Center(child: Text('Content of Tab 2')),
],
),
)
flutter 抛出的错误,
════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
The following assertion was thrown building KeyedSubtree-[<0>]:
A RenderPositionedBox expected a child of type RenderBox but received a child of type RenderSliverGrid.
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.
The RenderPositionedBox that expected a RenderBox child was created by: Center ← KeyedSubtree-[<0>] ← RepaintBoundary ← IndexedSemantics ← NotificationListener<KeepAliveNotification> ← KeepAlive ← AutomaticKeepAlive ← KeyedSubtree-[Key <[<0>]>] ← _SliverFillViewportRenderObjectWidget ← _SliverFractionalPadding ← SliverFillViewport ← Viewport ← ⋯
The RenderSliverGrid that did not match the expected child type was created by: SliverGrid ← Center ← KeyedSubtree-[<0>] ← RepaintBoundary ← IndexedSemantics ← NotificationListener<KeepAliveNotification> ← KeepAlive ← AutomaticKeepAlive ← KeyedSubtree-[Key <[<0>]>] ← _SliverFillViewportRenderObjectWidget ← _SliverFractionalPadding ← SliverFillViewport ← ⋯
The relevant error-causing widget was:
TabBarView file:///E:/Aviraj/Projects/syl/repo/ampere-iot-framework/mobile/flutter/sylcloud/lib/screens/device/device_details_screen.dart:108:18
When the exception was thrown, this was the stack:
#0 RenderObjectWithChildMixin.debugValidateChild.<anonymous closure> (package:flutter/src/rendering/object.dart:2866:9)
#1 RenderObjectWithChildMixin.debugValidateChild (package:flutter/src/rendering/object.dart:2893:6)
#2 SingleChildRenderObjectElement.insertChildRenderObject (package:flutter/src/widgets/framework.dart:5459:25)
#3 RenderObjectElement.attachRenderObject (package:flutter/src/widgets/framework.dart:5295:35)
#4 RenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5058:5)
有什么方法可以在上面的TabBarView中添加一个SliverGrid?
【问题讨论】:
标签: flutter dart flutter-sliver