[英]“A RenderFlex overflowed by 60 pixels on the bottom” error on flutter
[英]Flutter: How to fix "A RenderFlex overflowed by pixels " error?
我在Flutter
应用程序中使用GridView
来显示图像及其标题。 请检查以下代码。
import 'package:flutter/material.dart';
import '../common_ui/search_bar.dart';
class PurchaseProductsPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return PurchaseProductsUI();
}
}
class PurchaseProductsUI extends StatefulWidget {
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return _PurchaseProductUIState();
}
}
class _PurchaseProductUIState extends State<PurchaseProductsUI> {
@override
Widget build(BuildContext context) {
// TODO: implement build
return ListView(
children: <Widget>[
Container(
margin: EdgeInsets.all(20),
child: SearchBar(),
),
Container(
margin: EdgeInsets.all(20),
child: GridView.builder(
physics: ScrollPhysics(), // to disable GridView's scrolling
shrinkWrap: true,
itemCount: 20,
gridDelegate: new SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2),
itemBuilder: (BuildContext context, int index) {
return Container(
padding: EdgeInsets.all(5), child: _buildImageBoxes());
})),
],
);
}
Widget _buildImageBoxes() {
return
Column(
children: <Widget>[
Container(
child: Image.network("https://picsum.photos/200/300/?random"),
),
Container(
padding: EdgeInsets.all(10),
child: Text("Text"), )
],
);
}
}
运行上述代码时出现以下错误和 UI
I/flutter ( 2743): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 2743): The following message was thrown during layout:
I/flutter ( 2743): A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): The overflowing RenderFlex has an orientation of Axis.vertical.
I/flutter ( 2743): The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and
I/flutter ( 2743): black striped pattern. This is usually caused by the contents being too big for the RenderFlex.
I/flutter ( 2743): Consider applying a flex factor (e.g. using an Expanded widget) to force the children of the
I/flutter ( 2743): RenderFlex to fit within the available space instead of being sized to their natural size.
I/flutter ( 2743): This is considered an error condition because it indicates that there is content that cannot be
I/flutter ( 2743): seen. If the content is legitimately bigger than the available space, consider clipping it with a
I/flutter ( 2743): ClipRect widget before putting it in the flex, or using a scrollable container rather than a Flex,
I/flutter ( 2743): like a ListView.
I/flutter ( 2743): The specific RenderFlex in question is:
I/flutter ( 2743): RenderFlex#4a1bb OVERFLOWING
I/flutter ( 2743): creator: Column ← Padding ← Container ← RepaintBoundary-[<14>] ← IndexedSemantics ←
I/flutter ( 2743): NotificationListener<KeepAliveNotification> ← KeepAlive ← AutomaticKeepAlive ← SliverGrid ←
I/flutter ( 2743): MediaQuery ← SliverPadding ← ShrinkWrappingViewport ← ⋯
I/flutter ( 2743): parentData: offset=Offset(5.0, 5.0) (can use size)
I/flutter ( 2743): constraints: BoxConstraints(w=150.0, h=150.0)
I/flutter ( 2743): size: Size(150.0, 150.0)
I/flutter ( 2743): direction: vertical
I/flutter ( 2743): mainAxisAlignment: start
I/flutter ( 2743): mainAxisSize: max
I/flutter ( 2743): crossAxisAlignment: center
I/flutter ( 2743): verticalDirection: down
I/flutter ( 2743): ◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤
I/flutter ( 2743): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
I/flutter ( 2743): Another exception was thrown: A RenderFlex overflowed by 111 pixels on the bottom.
Reloaded 0 of 446 libraries in 1,179ms.
下面是用户界面
我该如何解决这个问题?
尝试在 _buildImageBoxes() 函数中使用 Expanded 而不是 Container
Widget _buildImageBoxes() {
return Column(
children: <Widget>[
Expanded(
child: Image.network("https://picsum.photos/500/500/?random"),
),
Container(
padding: EdgeInsets.all(10),
child: Text("Text"),
)
],
);
}
Expanded
→计算空间 Column
或Row
Expanded
或Flexible
小部件将使 Flutter 计算剩余空间并将该空间用于布局。
不在Expanded
或Flexible
中的小部件的布局与屏幕/约束空间无关。
Column
和Row
分为两个主要阶段:
Flexible
物品Flexible
项目( Expanded
和Flexible
小部件)Flutter 执行阶段 1 时没有考虑屏幕尺寸或任何其他限制。
Flutter 只是将所有非 flex-factor 项目大小加在一起。
屏幕或其他限制的总和太大? → RenderFlex overflowed
异常。
带有flex
构造函数参数的小部件是 flex-factor 项目。
即Flexible
或Expanded
小部件。 (也有Spacer
,但没有人使用它。)
在第 1 阶段之后,任何 flex-factor 小部件的布局都考虑到了剩余空间。
非灵活和弹性因子布局阶段之间的主要区别:
在Column
或Row
,将小部件包装在Expanded
或Flexible
,Flutter 将计算其布局的剩余空间。 这将防止问题中的RenderFlex overflowed
异常,因为每个Image
小部件都会根据空间限制调整自身大小。
但在第一阶段,没有空间限制。 所以Images
没有调整大小(和溢出)。
Column
或Row
未包含在Expanded
或Flexible
子小部件将以其固有大小进行布局,而不管屏幕/约束空间如何。
Space 400
Column
Image 150
Image 150
Image 150
总和非弹性图像:450。可用空间:400 → Overflowed
解决方案:使用阶段 2 → 使用计算空间
将Image
包装在 flex 小部件Expanded
,计算可用高度,然后在Expanded
之间共享(作为约束),并调整Image
大小以适应Expanded
约束:
Space 400
Column
Expanded 133
→ Image ←
Expanded 133
→ Image ←
Expanded 133
→ Image ←
Sum flex Expandeds: 399. Space: 400 → OK
Widget build(BuildContext context) {
final _screenSize = MediaQuery.of(context).size;
return Container(
height: _screenSize.height * 0.2,);
}
MediaQuery.of(context)
它对我有用!
在你的Image.network
方法中使用fit
属性来减小你的图像的大小,因为它们更大并且从你的容器中溢出,或者你可以通过它们的height
和width
属性来放大你的Containers
。
您也可以在使用启动屏幕键盘的TextField
时遇到此错误,以解决它设置
Scaffold(
resizeToAvoidBottomInset: false, // <-- Set it to false.
body: SingleChildScrollView(
child: Column(
children: [
SizedBox(height: 600),
TextField(),
],
),
),
)
在列/行中为您的孩子使用Expanded/Flexible
。
使用Expanded
:
Column( children: [ Expanded( flex: 1, child: Widget1(), ), Expanded( flex: 2, child: Widget2(), ) ], )
使用Flexible
:
Row( children: [ Flexible( flex: 1, child: Widget1(), ), Flexible( flex: 2, child: Widget2(), ) ], )
给出一个固定的高度:
Column( children: [ SizedBox( height: 200, child: Widget1(), ), Expanded( flex: 2, child: Widget2(), ) ], )
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