我正在尝试从 charts_flutter package 获取图表展开以填充可用空间，当它位于列内的行内时。我花了几个小时试图做到这一点，但我一定遗漏了一些东西!这在视觉上是我想要实现的目标:
这是一个最小的工作示例。我一定已经尝试了一百种扩展、灵活、主轴尺寸、交叉轴对齐等组合，但我似乎无法找到正确的组合。目前底部溢出无限像素，对象在布局期间被赋予无限大小。有 this open issue ，不知道有没有关系，也没有答案。我只需要帮助处理 runApp 中的一些代码:
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
void main() => runApp(
// HOW DO I LAY THIS OUT?
Column(
children: <Widget>[
Container(height: 200, color: Colors.orange),
Row(
textDirection: TextDirection.ltr,
children: <Widget>[
Container(width: 200,color: Colors.orange),
Expanded(child: SimpleTimeSeriesChart.withSampleData())
],
)
],
)
);
class SimpleTimeSeriesChart extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
SimpleTimeSeriesChart(this.seriesList, {this.animate});
factory SimpleTimeSeriesChart.withSampleData() {
return new SimpleTimeSeriesChart(
_createSampleData(),
animate: false,
);
}
@override
Widget build(BuildContext context) {
return new charts.TimeSeriesChart(
seriesList,
animate: animate,
dateTimeFactory: const charts.LocalDateTimeFactory(),
);
}
/// Create one series with sample hard coded data.
static List<charts.Series<TimeSeriesSales, DateTime>> _createSampleData() {
final data = [
new TimeSeriesSales(new DateTime(2017, 9, 19), 5),
new TimeSeriesSales(new DateTime(2017, 9, 26), 25),
new TimeSeriesSales(new DateTime(2017, 10, 3), 100),
new TimeSeriesSales(new DateTime(2017, 10, 10), 75),
];
return [
new charts.Series<TimeSeriesSales, DateTime>(
id: 'Sales',
colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
domainFn: (TimeSeriesSales sales, _) => sales.time,
measureFn: (TimeSeriesSales sales, _) => sales.sales,
data: data,
)
];
}
}
class TimeSeriesSales {
final DateTime time;
final int sales;
TimeSeriesSales(this.time, this.sales);
}
最佳答案
**在第 8 步查看原因 - 向下滚动? **
I'm trying to get a chart from the charts_flutter package to expand to fill available space
object was given an infinite size during layout
用扩展包住行
Column(children: <Widget>[Expanded(child: Row())])
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
void main() => runApp(
// HOW DO I LAY THIS OUT?
Column(
children: <Widget>[
Container(height: 200, color: Colors.orange),
Expanded(
child: Row(
textDirection: TextDirection.ltr,
children: <Widget>[
Container(width: 200, color: Colors.green),
Expanded(child: SimpleTimeSeriesChart.withSampleData()),
],
),
)
],
));
class SimpleTimeSeriesChart extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
SimpleTimeSeriesChart(this.seriesList, {this.animate});
factory SimpleTimeSeriesChart.withSampleData() {
return new SimpleTimeSeriesChart(
_createSampleData(),
animate: false,
);
}
@override
Widget build(BuildContext context) {
return new charts.TimeSeriesChart(
seriesList,
animate: animate,
dateTimeFactory: const charts.LocalDateTimeFactory(),
);
}
/// Create one series with sample hard coded data.
static List<charts.Series<TimeSeriesSales, DateTime>> _createSampleData() {
final data = [
new TimeSeriesSales(new DateTime(2017, 9, 19), 5),
new TimeSeriesSales(new DateTime(2017, 9, 26), 25),
new TimeSeriesSales(new DateTime(2017, 10, 3), 100),
new TimeSeriesSales(new DateTime(2017, 10, 10), 75),
];
return [
new charts.Series<TimeSeriesSales, DateTime>(
id: 'Sales',
colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
domainFn: (TimeSeriesSales sales, _) => sales.time,
measureFn: (TimeSeriesSales sales, _) => sales.sales,
data: data,
)
];
}
}
class TimeSeriesSales {
final DateTime time;
final int sales;
TimeSeriesSales(this.time, this.sales);
}
I/flutter ( 4228): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 4228): ════════════════════════════════════════════════════════════════════════════════════════════════════
用你的眼睛扫描错误你会看到一些像
这样的短语I/flutter ( 4228): constraints: BoxConstraints(w=320.0, h=480.0)
I/flutter ( 4228): The following assertion was thrown during performLayout():
I/flutter ( 4228): Summary 1: RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
这是一个框约束错误
阅读更多:
接近尾声它会给你来源:
I/flutter ( 4228): creator: CustomMultiChildLayout ← TimeSeriesChart ← SimpleTimeSeriesChart ← Expanded ← Row ← Column
I/flutter ( 4228): ← [root]
接近尾声它会给你缺少的约束
I/flutter ( 4228): constraints: BoxConstraints(w=120.0, 0.0<=h<=Infinity)
注意:0.0<><>
高度不能是无穷大
用 SizedBox 扭曲源代码以确保它是什么引发了错误，看看它是否解决了问题
A box with a specified size.
If given a child, this widget forces its child to have a specific width and/or height (assuming values are permitted by this widget's parent). If either the width or height is null, this widget will size itself to match the child's size in that dimension.
TimeSeriesChart(child) 向 Raw(parent) 询问高度
Raw(child) 向 Column(parent) 询问高度
专栏不知道
为什么 Column 不知道，因为默认行为是它会让 children 自己决定自己的高度
但我们可以告诉 Column children 不知道，所以将他们扩展到可用空间
I/flutter ( 4228): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 4228): The following assertion was thrown during performLayout():
I/flutter ( 4228): FlutterError contained multiple error summaries.
I/flutter ( 4228): All FlutterError objects should have only a single short (one line) summary description of the
I/flutter ( 4228): problem that was detected.
I/flutter ( 4228): Malformed FlutterError:
I/flutter ( 4228): RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter ( 4228): This probably means that it is a render object that tries to be as big as possible, but it was put
I/flutter ( 4228): inside another render object that allows its children to pick their own size.
I/flutter ( 4228): RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter ( 4228): This probably means that it is a render object that tries to be as big as possible, but it was put
I/flutter ( 4228): inside another render object that allows its children to pick their own size.
I/flutter ( 4228): The nearest ancestor providing an unbounded height constraint is: RenderFlex#d29e7 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter ( 4228): creator: Column ← [root]
I/flutter ( 4228): parentData: <none>
I/flutter ( 4228): constraints: BoxConstraints(w=320.0, h=480.0)
I/flutter ( 4228): size: MISSING
I/flutter ( 4228): direction: vertical
I/flutter ( 4228): mainAxisAlignment: start
I/flutter ( 4228): mainAxisSize: max
I/flutter ( 4228): crossAxisAlignment: center
I/flutter ( 4228): verticalDirection: down
I/flutter ( 4228): The constraints that applied to the RenderCustomMultiChildLayoutBox were:
I/flutter ( 4228): BoxConstraints(w=120.0, 0.0<=h<=Infinity)
I/flutter ( 4228): The exact size it was given was:
I/flutter ( 4228): Size(120.0, Infinity)
I/flutter ( 4228): See https://flutter.dev/docs/development/ui/layout/box-constraints for more information.
I/flutter ( 4228):
I/flutter ( 4228): The malformed error has 2 summaries.
I/flutter ( 4228): Summary 1: RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter ( 4228): Summary 2: RenderCustomMultiChildLayoutBox object was given an infinite size during layout.
I/flutter ( 4228):
I/flutter ( 4228): This error should still help you solve your problem, however please also report this malformed error
I/flutter ( 4228): in the framework by filing a bug on GitHub:
I/flutter ( 4228): https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter ( 4228):
I/flutter ( 4228): When the exception was thrown, this was the stack:
I/flutter ( 4228): #0 new FlutterError.fromParts.<anonymous closure> (package:flutter/src/foundation/assertions.dart:540:9)
I/flutter ( 4228): #1 new FlutterError.fromParts (package:flutter/src/foundation/assertions.dart:543:6)
I/flutter ( 4228): #2 RenderBox.debugAssertDoesMeetConstraints.<anonymous closure> (package:flutter/src/rendering/box.dart:1966:28)
I/flutter ( 4228): #3 RenderBox.debugAssertDoesMeetConstraints (package:flutter/src/rendering/box.dart:2029:6)
I/flutter ( 4228): #4 RenderBox.size=.<anonymous closure> (package:flutter/src/rendering/box.dart:1740:7)
I/flutter ( 4228): #5 RenderBox.size= (package:flutter/src/rendering/box.dart:1742:6)
I/flutter ( 4228): #6 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:355:5)
I/flutter ( 4228): #7 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter ( 4228): #8 RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:805:17)
I/flutter ( 4228): #9 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter ( 4228): #10 RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:743:15)
I/flutter ( 4228): #11 RenderObject.layout (package:flutter/src/rendering/object.dart:1619:7)
I/flutter ( 4228): #12 RenderView.performLayout (package:flutter/src/rendering/view.dart:151:13)
I/flutter ( 4228): #13 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1496:7)
I/flutter ( 4228): #14 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:765:18)
I/flutter ( 4228): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:346:19)
I/flutter ( 4228): #16 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:701:13)
I/flutter ( 4228): #17 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:285:5)I/flutter ( 4228): #18 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1016:15)
I/flutter ( 4228): #19 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:958:9)
I/flutter ( 4228): #20 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:784:7)
I/flutter ( 4228): #29 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:382:19)
I/flutter ( 4228): #30 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:416:5)
I/flutter ( 4228): #31 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)
I/flutter ( 4228): (elided 8 frames from package dart:async and package dart:async-patch)
I/flutter ( 4228):
I/flutter ( 4228): The following RenderObject was being processed when the exception was fired: RenderCustomMultiChildLayoutBox#e4ae0 relayoutBoundary=up2 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
I/flutter ( 4228): creator: CustomMultiChildLayout ← TimeSeriesChart ← SimpleTimeSeriesChart ← Expanded ← Row ← Column
I/flutter ( 4228): ← [root]
I/flutter ( 4228): parentData: offset=Offset(0.0, 0.0); flex=1; fit=FlexFit.tight (can use size)
I/flutter ( 4228): constraints: BoxConstraints(w=120.0, 0.0<=h<=Infinity)
I/flutter ( 4228): size: Size(120.0, Infinity)
I/flutter ( 4228): This RenderObject had the following descendants (showing up to depth 5):
I/flutter ( 4228): child 1: RenderSemanticsGestureHandler#2034c NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 4228): child: RenderPointerListener#aef29 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
I/flutter ( 4228): child: ChartContainerRenderObject<DateTime>#b28fc NEEDS-LAYOUT NEEDS-PAINT
I/flutter ( 4228): ════════════════════════════════════════════════════════════════════════════════════════════════════
但如果它没有高度，它会询问它的父级，行
但是行没有固定的高度，它会询问 child
但是 child 没有固定的高度，它会询问行父
但是父级没有给它的子级(行)一个固定的高度
关于嵌套行/列中的 Flutter 扩展图表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57655660/
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