我正在尝试使用Flutter编写应用程序，但每次添加ListView时，都会在运行时抛出以下异常：Vertical viewport was given unbounded height。 ListView没有嵌套在另一个可滚动的小部件中，即使我使用文档中的ListView.builder示例代码，我也会收到错误。
以下是导致问题的代码：
import 'package:flutter/material.dart';
import '../ui/app_drawer.dart';
import '../ui/fgroup_button.dart';
import '../ui/custom_icons.dart';
import '../screens/cereales.dart';
class DayDisplay extends StatefulWidget {
final List<String> title;
final List<Map<String, int>> values;
DayDisplay(List<String> title, List<Map<String, int>> values):
this.title = title, this.values = values;
@override
_DayDisplayState createState() => new _DayDisplayState();
}
class _DayDisplayState extends State<DayDisplay> {
int index = 0;
@override
Widget build(BuildContext context) {
return new Column(
children: <Widget>[
new Container(
margin: EdgeInsetsDirectional.only(top:5.0) ,
child: new Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(widget.title[index], textAlign: TextAlign.center, style: new TextStyle(fontWeight: FontWeight.bold, fontSize: 42.0),),
new Text('Cereales: ${widget.values[index]['cereales']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Fruta: ${widget.values[index]['fruta']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Verdura: ${widget.values[index]['verdura']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Leguminosa: ${widget.values[index]['leguminosa']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Poa: ${widget.values[index]['poa']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Grasa: ${widget.values[index]['grasa']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Azucar: ${widget.values[index]['azucar']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
new Text('Leche: ${widget.values[index]['leche']}', textAlign: TextAlign.center, style: new TextStyle(fontSize: 18.0)),
],
),
),
new Container(
margin: EdgeInsetsDirectional.only(top:8.0,),
child: new Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [ButtonTheme.bar(
child: new ButtonBar(
children: <Widget>[
new FlatButton(onPressed: () {
this.setState(() => index = 0);
}, child: new Text('Antes del ejercicio'), color: Colors.green),
new FlatButton(onPressed: () {
this.setState(() => index = 1);
}, child: new Text('Desayuno'), color: Colors.green,),
new FlatButton(onPressed: () {
this.setState(() => index = 2);
}, child: new Text('Colacion'), color: Colors.green,),
],
),
),
]
),
),
new Container(
margin: EdgeInsetsDirectional.only(top:4.0, bottom: 4.0),
child: new Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [ButtonTheme.bar(
child: new ButtonBar(
children: <Widget>[
new FlatButton(onPressed: () {
this.setState(() => index = 0);
}, child: new Text('Comida'), color: Colors.green),
new FlatButton(onPressed: () {
this.setState(() => index = 1);
}, child: new Text('Colacion'), color: Colors.green,),
new FlatButton(onPressed: () {
this.setState(() => index = 2);
}, child: new Text('Cena'), color: Colors.green,),
],
),
),
]
),
),
],
);
}
}
class HomePage extends StatefulWidget {
const HomePage({ Key key}) : super(key: key);
@override
_HomePageState createState() => new _HomePageState();
}
class _HomePageState extends State<HomePage> {
var dayValues = [
{
'cereales': 1,
'fruta': 2,
'verdura': 3,
'leguminosa': 4,
'poa': 5,
'grasa': 6,
'azucar': 7,
'leche': 8
},
{
'cereales': 2,
'fruta': 4,
'verdura': 6,
'leguminosa': 8,
'poa': 10,
'grasa': 12,
'azucar': 14,
'leche': 16
},
{
'cereales': 3,
'fruta': 6,
'verdura': 9,
'leguminosa': 12,
'poa': 5,
'grasa': 6,
'azucar': 7,
'leche': 8
},
];
var dayTitles = [
'Antes del Ejercicio',
'Desayuno',
'Colacion Mañana',
'Comida',
'Colacion Tarde',
'Cena'
];
@override
Widget build(BuildContext context) {
var dayDisplay = new DayDisplay(dayTitles, dayValues);
return new Scaffold(
appBar: new AppBar(
title: new Text("Verde Limón"),
backgroundColor: Colors.green
),
drawer: new AppDrawer(),
floatingActionButton: new FloatingActionButton(
onPressed: null,
tooltip: 'Añadir Puntos',
child: new Icon(Icons.add)
),
body: new Column(
children: <Widget>[
dayDisplay,
Divider(),
Container(
child: new ListView(
children: <Widget>[
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
FGroupButton('Cereales', Colors.yellow[800], 12, CerealesPage(), Icon(Icons.fastfood, color:Colors.white)),
],
),
)
],
),
);
}
}
我不知道是不是可以导致问题，我在我正在处理的另一个应用程序中以相同的方式添加了ListView，它工作得很好。如果您需要导入的任何其他代码，请求它，我会发布它。 这是完整的错误日志：
I/flutter ( 4625): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 4625): The following assertion was thrown during performResize():
I/flutter ( 4625): Vertical viewport was given unbounded height.
I/flutter ( 4625): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter ( 4625): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter ( 4625): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter ( 4625): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter ( 4625): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter ( 4625): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter ( 4625): the height of the viewport to the sum of the heights of its children.
I/flutter ( 4625):
I/flutter ( 4625): When the exception was thrown, this was the stack:
I/flutter ( 4625): #0 RenderViewport.performResize.<anonymous closure> (package:flutter/src/rendering/viewport.dart:944:15)
I/flutter ( 4625): #1 RenderViewport.performResize (package:flutter/src/rendering/viewport.dart:997:6)
I/flutter ( 4625): #2 RenderObject.layout (package:flutter/src/rendering/object.dart:1555:9)
I/flutter ( 4625): #3 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #4 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #5 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #6 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #7 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #8 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #9 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #10 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #11 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #12 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #13 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #14 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #15 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #16 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #17 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #18 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #19 RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:738:15)
I/flutter ( 4625): #20 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #21 MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:141:11)
I/flutter ( 4625): #22 _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:399:7)
I/flutter ( 4625): #23 MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:211:7)
I/flutter ( 4625): #24 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:355:14)
I/flutter ( 4625): #25 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #26 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #27 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #28 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #29 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1143:11)
I/flutter ( 4625): #30 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #31 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #32 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #33 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #34 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #35 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #36 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #37 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #38 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #39 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #40 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #41 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #42 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #43 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #44 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #45 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #46 RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:2809:13)
I/flutter ( 4625): #47 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #48 RenderStack.performLayout (package:flutter/src/rendering/stack.dart:520:15)
I/flutter ( 4625): #49 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #50 __RenderTheatre&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #51 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #52 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #53 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #54 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #55 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #56 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #57 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #58 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #59 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #60 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter ( 4625): #61 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter ( 4625): #62 RenderView.performLayout (package:flutter/src/rendering/view.dart:125:13)
I/flutter ( 4625): #63 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1445:7)
I/flutter ( 4625): #64 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:709:18)
I/flutter ( 4625): #65 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:270:19)
I/flutter ( 4625): #66 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:627:13)
I/flutter ( 4625): #67 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
I/flutter ( 4625): #68 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter ( 4625): #69 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter ( 4625): #70 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:751:7)
I/flutter ( 4625): #72 _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
I/flutter ( 4625): #73 _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
I/flutter ( 4625): #74 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12)
I/flutter ( 4625): (elided one frame from package dart:async)
I/flutter ( 4625):
I/flutter ( 4625): The following RenderObject was being processed when the exception was fired:
I/flutter ( 4625): RenderViewport#f0f8d NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): creator: Viewport ← _ScrollableScope ← IgnorePointer-[GlobalKey#74b2b] ← Semantics ← Listener ←
I/flutter ( 4625): _GestureSemantics ← RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#a26e1] ←
I/flutter ( 4625): _ExcludableScrollSemantics-[GlobalKey#d886a] ← RepaintBoundary ← CustomPaint ← RepaintBoundary ←
I/flutter ( 4625): NotificationListener<ScrollNotification> ← ⋯
I/flutter ( 4625): parentData: <none> (can use size)
I/flutter ( 4625): constraints: BoxConstraints(0.0<=w<=411.4, 0.0<=h<=Infinity)
I/flutter ( 4625): size: MISSING
I/flutter ( 4625): axisDirection: down
I/flutter ( 4625): crossAxisDirection: right
I/flutter ( 4625): offset: ScrollPositionWithSingleContext#96d55(offset: 0.0, range: null..null, viewport: null,
I/flutter ( 4625): ScrollableState, AlwaysScrollableScrollPhysics -> ClampingScrollPhysics, IdleScrollActivity#988d8,
I/flutter ( 4625): ScrollDirection.idle)
I/flutter ( 4625): anchor: 0.0
I/flutter ( 4625): This RenderObject had the following descendants (showing up to depth 5):
I/flutter ( 4625): RenderSliverPadding#4f8e1 NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): RenderSliverList#af3ad NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): RenderRepaintBoundary#630d9 NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): RenderSemanticsAnnotations#53c3c NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): RenderPadding#086f3 NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderViewport#f0f8d NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderViewport#f0f8d NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#f38ea relayoutBoundary=up9 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#7561c relayoutBoundary=up8 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderPointerListener#76fd2 relayoutBoundary=up7 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#29de7 relayoutBoundary=up6 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: _RenderExcludableScrollSemantics#087de relayoutBoundary=up5 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#d7d18 relayoutBoundary=up4 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderCustomPaint#dc8bc relayoutBoundary=up3 NEEDS-PAINT
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#037d4 relayoutBoundary=up2 NEEDS-PAINT
Reloaded 3 of 394 libraries in 6,616ms.
I/flutter ( 4625): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#037d4 relayoutBoundary=up2 NEEDS-PAINT
提前感谢您的帮助。
答案 0 :(得分：6)
使用Expanded小部件包装ListView。
new Expanded(
child: new ListView(
.....
)
);
这告诉ListView尽可能多地获取宽度和高度。
答案 1 :(得分：4)
您可以为shrinkWrap = true指定ListView来修复例外。
ListView(
shrinkWrap: true,
children...
)
这在异常消息中说明。原因也在异常消息中说明。
在这个特定的情况下，我不是特别确定树中的哪个Widget会导致这种情况，但我认为这是不相关的。我不知道Container关于ListView的内容是什么。我会先将它包裹在Column周围，但shrinkWrap应该可以解决问题。
答案 2 :(得分：0)
只包装到容器中并赋予其高度
timestamp