Flutter PieChart 标签——如何让它工作答案

【问题标题】：Flutter PieChart Labels --how to make it worksFlutter PieChart 标签——如何让它工作
【发布时间】：2021-12-22 10:01:51
【问题描述】：

我试图让我的 PieChart 标签可见，但是在设置 arcRenderDecorators 之后它就出现了

RenderBox 未布置：ChartContainerRenderObject#1bf0d NEEDS-PAINT 'package:flutter/src/rendering/box.dart': 断言失败：第 1927 行第 12 行：'hasSize'
RenderBox 未布置：RenderPointerListener#5ff88 需要-绘制需要-合成-位-更新 'package:flutter/src/rendering/box.dart': 断言失败：第 1927 行第 12 行：'hasSize'
RenderBox 未布置：RenderSemanticsGestureHandler#4a473 需要-绘制需要-合成-位-更新 'package:flutter/src/rendering/box.dart': 断言失败：第 1927 行第 12 行：'hasSize'
RenderBox 未布置：ChartContainerRenderObject#1bf0d 'package:flutter/src/rendering/box.dart': 断言失败：第 1927 行第 12 行：'hasSize' 问题。

我必须使用什么样的小部件才能做到这一点。请帮忙。

 final List<DeveloperSeries> data = [

   DeveloperSeries(
     year: "2017",
     developers: 40000,
     barColor: charts.ColorUtil.fromDartColor(Colors.blue),
   ),
   DeveloperSeries(
     year: "2019",
     developers: 40000,
     barColor: charts.ColorUtil.fromDartColor(Colors.blue),
   ),
   DeveloperSeries(
     year: "2020",
     developers: 35000,
     barColor: charts.ColorUtil.fromDartColor(Colors.blue),
   ),
   DeveloperSeries(
     year: "2021",
     developers: 45000,
     barColor: charts.ColorUtil.fromDartColor(Colors.blue),
   ),
 ];

 @override
 Widget build(BuildContext context) {
   return Scaffold(
     body: Center(
       child: DeveloperChart(
         data: data,
       )
     ),
   );
 }
}
class DeveloperChart extends StatelessWidget {
 final List<DeveloperSeries> data;

 DeveloperChart({required this.data});

 @override
 Widget build(BuildContext context) {
   List<charts.Series<DeveloperSeries, String>> series = [
     charts.Series(
       id: "developers",
       data: data,
       domainFn: (DeveloperSeries series, _) => series.year,
       measureFn: (DeveloperSeries series, _) => series.developers,
       colorFn: (DeveloperSeries series, _) => series.barColor,
       labelAccessorFn: (DeveloperSeries row, _) => row.year,
     )
   ];

   return Container(
       height: 500,
       width: 500,
       child: Card(
         child: Padding(
           padding: const EdgeInsets.all(9.0),
           child: Column(
               children: <Widget>[
                 Text(
                   "Yearly Growth in the Flutter Community",
                   style: Theme
                       .of(context)
                       .textTheme
                       .bodyText2,
                 ),
                 Expanded(
                     child: charts.PieChart(series, animate: true,
                         defaultRenderer: charts.ArcRendererConfig(
                             arcRendererDecorators: [
                               charts.ArcLabelDecorator(
                                   labelPosition: charts.ArcLabelPosition
                                       .outside)
                             ])
                     )
                 )
               ]
           ),
         ),
       )
   );
 }
}```

【问题讨论】：

标签： flutter charts

【解决方案1】：

同样的问题，我通过替换解决了：

charts.PieChart(

与：

charts.PieChart<String>(

【讨论】：