Flutter Web - 不支持的操作：卡片小部件中画布的 NaN 错误

问题描述

我正在做一个颤振网络项目。我们使用库 fl_chart。我们想在 PieChart 小部件中使用 Card，但它抛出错误 Unsupported operation: NaN。它在调试和发布模式下发生（从命令行 Flutter run lib/main.dart 和 Flutter run --release lib/main.dart 启动），但在通过 VSCode 调试器启动应用程序时不会发生。

这是一个小例子 (main.dart)：

import 'package:fl_chart/fl_chart.dart';
import 'package:Flutter/material.dart';

class PieChartTest extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Card(    // <- If you change it to a Container,it is working fine
          child: PieChart(
            PieChartData(
              sections: [
                PieChartSectionData(
                  value: 4.0,title: 'Section 1',color: Colors.blue,),PieChartSectionData(
                  value: 6.0,title: 'Section 2',color: Colors.red,],);
  }
}

Future<void> main() async {
  runApp(PieCharttest());
}

这是日志

══╡ EXCEPTION CAUGHT BY SCHEDULER LIBRARY
╞═════════════════════════════════════════════════════════
The following UnsupportedError was thrown during a scheduler callback:
Unsupported operation: NaN

When the exception was thrown,this was the stack:
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 216:49  throw_
dart-sdk/lib/_internal/js_dev_runtime/private/js_number.dart 80:5             toInt]
dart-sdk/lib/_internal/js_dev_runtime/private/js_number.dart 87:32            ceil]
lib/_engine/engine/bitmap_canvas.dart 176:52
_widthToPhysical
lib/_engine/engine/bitmap_canvas.dart 120:32                                  new
lib/_engine/engine/html/picture.dart 518:33
[_findOrCreateCanvas]
lib/_engine/engine/html/picture.dart 433:21
paintCallback
lib/_engine/engine/html/surface.dart 49:16
commitScene
lib/_engine/engine/html/scene_builder.dart 552:7                              <fn>
lib/_engine/engine/profiler.dart 36:18
timeAction
lib/_engine/engine/html/scene_builder.dart 546:12                             build
packages/Flutter/src/rendering/layer.dart 770:35
buildScene
packages/Flutter/src/rendering/view.dart 231:30
compositeFrame
packages/Flutter/src/rendering/binding.dart 458:18                            drawFrame
packages/Flutter/src/widgets/binding.dart 900:13                              drawFrame
packages/Flutter/src/rendering/binding.dart 320:5
[_handlePersistentFrameCallback]
packages/Flutter/src/scheduler/binding.dart 1119:15
[_invokeFrameCallback]
packages/Flutter/src/scheduler/binding.dart 1057:9
handleDrawFrame
packages/Flutter/src/scheduler/binding.dart 865:7                             <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:19
internalCallback
═══════════════════════════════════════════════════════════════════════════════════════
═════════════
Another exception was thrown: Unsupported operation: NaN

我使用的是 Flutter 1.25.0-8.1.pre 测试版

---

这是怎么回事，为什么？

还有我该如何解决这个问题或者有什么解决办法？

---

编辑：

它也不适用于 Flutter 1.25.0-8.3.pre • channel beta 并遇到相同的问题。 它适用于 Flutter 1.26.0-17.1.pre • channel dev 。

但是我们使用的项目需要测试版。

它使用选项 --web-renderer canvaskit 工作，但我想继续使用 html 选项。

解决方法

HTML Web Renderer 可能不支持。

尝试使用 CanvasKit Web Renderer。

flutter run -d chrome --web-renderer canvaskit .\lib\main.dart

,

即使在调试模式下也能正常工作。

不过，我使用的是 stable version 1.22.5。