RenderCustomMultiChildLayoutBox 对象在布局期间被赋予了无限大小。颤振错误
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【中文标题】RenderCustomMultiChildLayoutBox 对象在布局期间被赋予了无限大小。颤振错误【英文标题】：RenderCustomMultiChildLayoutBox object was given an infinite size during layout. flutter error 【发布时间】：2019-05-13 05:22:39 【问题描述】：我是 Flutter 的新手，正在尝试在 Flutter 中实现自定义列表视图。 在布局错误期间，它的给定 RenderCustomMultiChildLayoutBox 对象被赋予了无限大小
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我无法获取哪个小部件的抛出错误
2 另外请建议如何调试这些布局错误，因为错误跟踪没有引发错误的特定小部件信息
请在下面找到相同的代码：
class ChatItemSreen extends StatelessWidget
var leftSection;
var middleSection;
var rightSection;
ChatModel _chartObj;
ChatItemSreen(ChatModel _chartObj)
this._chartObj = _chartObj;
//.........the left section ...........................
CircleAvatar image = new CircleAvatar(
backgroundColor: Colors.lightGreen,
backgroundImage: new NetworkImage(this._chartObj.geturl()),
radius: 24.0,
);
leftSection = new Container(child: image);
//.........the middle section ...........................
middleSection = new Expanded(
child: new Container(
padding: new EdgeInsets.only(left: 8.0),
child: new Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
new Text(this._chartObj.getuserName(),
style: new TextStyle(
color: Colors.black,
fontWeight: FontWeight.w300,
fontSize: 16.0)),
new Text(this._chartObj.getmessage(),
style: new TextStyle(color: Colors.grey))
],
),
));
//.........the right section ...........................
rightSection = new Container(
child: new Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
new Text(this._chartObj.gettimeStamp()),
new CircleAvatar(
backgroundColor: Colors.lightGreen,
radius: 12.0,
child: new Text(
this._chartObj.getunreadMsgNo(),
style: new TextStyle(color: Colors.white, fontSize: 12.0),
))
],
),
);
@override
Widget build(BuildContext context)
return new Scaffold(
body: new Container(
margin: new EdgeInsets.all(2.0),
child: new Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[leftSection, middleSection, rightSection],
)),
);
void main() => runApp(MyApp());
class MyApp extends StatelessWidget
@override
Widget build(BuildContext context)
return MaterialApp(title: "Shashank List", home: RandomWords());
class RowItemState extends State<RandomWords>
final List<ChatModel> items = new List();
@override
void initState()
super.initState();
setState(()
items.add(new ChatModel("http://img2.thejournal.ie/inline/2470754/original?width=428&version=2470754", "9:35", "2", "Shashank", "Missed vedio call!!"));
items.add(new ChatModel("http://img2.thejournal.ie/inline/2470754/original?width=428&version=2470754", "10:35", "3", "Kakroo", "Missed vedio call!!"));
items.add(new ChatModel("http://img2.thejournal.ie/inline/2470754/original?width=428&version=2470754", "02:45", "4", "Alpha 1", "Missed vedio call!!"));
items.add(new ChatModel("http://img2.thejournal.ie/inline/2470754/original?width=428&version=2470754", "12:30", "6", "Beta 2", "Missed vedio call!!"));
);
@override
Widget build(BuildContext context)
return MaterialApp(
home: ListView.builder(
itemCount: items.length,
itemBuilder: (context,position)
ChatModel obj = items.elementAt(position);
return new ChatItemSreen(obj);
),
);
给我以下错误：
XCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (15078): The following assertion was thrown during performLayout():
I/flutter (15078): RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter (15078): This probably means that it is a render object that tries to be as big as possible, but it was put
I/flutter (15078): inside another render object that allows its children to pick their own size.
I/flutter (15078): The nearest ancestor providing an unbounded height constraint is:
I/flutter (15078): RenderIndexedSemantics#a9825 relayoutBoundary=up3 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (15078): creator: IndexedSemantics ← NotificationListener<KeepAliveNotification> ← KeepAlive ←
I/flutter (15078): AutomaticKeepAlive ← SliverList ← MediaQuery ← SliverPadding ← Viewport ← _ScrollableScope ←
I/flutter (15078): IgnorePointer-[GlobalKey#e8d9b] ← Semantics ← Listener ← ⋯
I/flutter (15078): parentData: index=0; layoutOffset=0.0 (can use size)
I/flutter (15078): constraints: BoxConstraints(w=411.4, 0.0<=h<=Infinity)
I/flutter (15078): semantic boundary
I/flutter (15078): size: MISSING
I/flutter (15078): index: 0
I/flutter (15078): The constraints that applied to the RenderCustomMultiChildLayoutBox were:
I/flutter (15078): BoxConstraints(w=411.4, 0.0<=h<=Infinity)
I/flutter (15078): The exact size it was given was:
I/flutter (15078): Size(411.4, Infinity)
I/flutter (15078): See https://flutter.io/layout/ for more information.
【问题讨论】：
我有完全相同的问题，w=411.4 的大小完全相同
【参考方案1】：
只需用 SizedBox 包裹小部件，并在 MediaQuery 的帮助下给出屏幕大小。
大小 size = MediaQuery.of(context).size;
SizedBox(height: size.height,width: size.height,child: Your Widget)
【讨论】：
【参考方案2】：日志说盒子约束高度设置为无穷大，这给出了盒子的无限大小
问题是因为ListView.builder 的高度不受限制，但没有 Sized 小部件子或父作为其大小的基础。
只需注意一件事：如果小部件未呈现，则该上下文可能不存在。这可能会导致出现问题
ListView
因为小部件仅在可能可见时才会呈现。
您可以在 LayoutBuilder 中进行包装：
@override
Widget build(BuildContext context)
return MaterialApp(
home: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints)
// height: constraints.maxHeight,
// width: constraints.maxWidth
return ListView.builder(
itemCount: items.length,
itemBuilder: (context, position)
ChatModel obj = items.elementAt(position);
return new ChatItemSreen(obj);
);
);
);
【讨论】：
【参考方案3】：我在尝试在单独的文本段落中包含一个可缩放的PhotoView 小部件时遇到了这个确切的问题。
当您编译并运行该应用程序时，您可能会注意到您的违规小部件应该是一个无限长的黑色区域。
错误的第二行写着
在布局期间被赋予了无限大小
这意味着需要限制小部件的大小。
我的解决方案是将PhotoView 包装在SizedBox 小部件中。
...
Text("Here's some text.\nAnd then there's this image:\n"),
SizedBox(
width: 200.0,
height: 300.0,
child: PhotoView(
imageProvider: NetworkImage("http://image/url/here.jpg"),
heroTag: "Lauren Mayberry",
),
),
Text("And now more text"),
...
在此示例中，我使用了固定的宽度和高度，但您始终可以根据其中的任何内容动态调整小部件的大小。
关于如何更好地调试布局错误：我唯一的建议是一次删除一个小部件，直到错误消失。这当然不太理想，但确实有效。
【讨论】：
我将它用于谷歌地图。现在我在SingleChildScrollView 中使用SizedBox。我已经删除了width: 并在SizedBox 中添加了height: 360.0,，所以它需要全宽。它完美地工作！谢谢。以上是关于RenderCustomMultiChildLayoutBox 对象在布局期间被赋予了无限大小。颤振错误的主要内容，如果未能解决你的问题，请参考以下文章