Flutter Web - 不支持的操作：卡片小部件中画布的 NaN 错误

Question

我正在开发一个 Flutter Web 项目。我们使用库fl_chart。我们想在Card 小部件中使用PieChart，但它会引发错误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

我正在使用 Flutter 1.25.0-8.1.pre beta

---

发生了什么，为什么？

还有我该如何解决这个问题或者有什么解决方法？

---

编辑：

它也不适用于 Flutter 1.25.0-8.3.pre • channel beta 并遇到同样的问题。 它适用于 Flutter 1.26.0-17.1.pre • channel dev 。

但是我们使用的项目需要beta通道。

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

Answer 1

HTML Web Renderer 可能不支持。

尝试使用 CanvasKit Web 渲染器。

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

Answer 2

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。