エラーログ

そのままやると:

  Widget build(BuildContext context) {
    if (_controller.hasClients) {
      _controller.jumpTo(0.0);
Performing hot reload...
Syncing files to device iPhone XR...
Reloaded 1 of 553 libraries in 949ms.
flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building MyWidget(dirty, dependencies:
flutter: [_LocalizationsScope-[GlobalKey#ab210], _InheritedTheme], state: _MyWidgetState#100b7):
flutter: Unexpected call to replaceSemanticsActions() method of RawGestureDetectorState.
flutter: The replaceSemanticsActions() method can only be called outside of the build phase.
&lt;cite class="hatena-citation"&gt;&lt;a href="https://medium.com/@diegoveloper/flutter-lets-know-the-scrollcontroller-and-scrollnotification-652b2685a4ac"&gt;medium.com&lt;/a&gt;&lt;/cite&gt;&lt;/p&gt;
&lt;li&gt;今回はjumpTo を使ったけどanimateTo などもある&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fflutterbyexample.com%2Fstateful-widget-lifecycle%2F" title="Stateful Widget Lifecycle" class="embed-card embed-webcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 155px; max-width: 500px; margin: 10px 0px;"/&gt;&lt;cite class="hatena-citation"&gt;&lt;a href="https://flutterbyexample.com/stateful-widget-lifecycle/"&gt;flutterbyexample.com&lt;/a&gt;&lt;/cite&gt;&lt;/p&gt;
&lt;li&gt;(re) build の後に必ず呼ばれるメソッドが見つけられなかった。というかどこかにオフィシャルドキュメントありそう&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fstackoverflow.com%2Fa%2F54553143%2F1380850" title="Flutter: Run method on Widget build complete" class="embed-card embed-webcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 155px; max-width: 500px; margin: 10px 0px;"/&gt;&lt;cite class="hatena-citation"&gt;&lt;a href="https://stackoverflow.com/a/54553143/1380850"&gt;stackoverflow.com&lt;/a&gt;&lt;/cite&gt;&lt;/p&gt;
&lt;li&gt;自分はエラーメッセージから類推して「flutter how to add task after build phase has finished」でググって行き着いた&lt;/li&gt;

推荐文章

伤情的凉茶 · On Windows, how do you get time in nanoseconds in C?

1 周前

谦和的牙膏 · [meta-freescale] How do I add the QSQLITE driver to the yocto build for wandboard

1 周前

害羞的咖啡豆 · 更新 IDE 和 SDK 工具 | Android Studio | Android Developers

6 天前

听话的楼房 · Splash screen breaks build for SDK lower than v26 · Issue #1503 · apache/cordova-android · GitHub

4 天前

老实的电梯 · Azure Functions – Serverless Functions in Computing | Microsoft Azure

1小时前

刚毅的紫菜 · 守护光明的大国工匠_王进

9 月前

深情的黄瓜 · Slurm Can't find plugin for select/linear / Newbie Corner / Arch Linux Forums

1 年前

爱逃课的墨镜 · 天下网商

1 年前

腼腆的桔子 · 北京魏桥国科新能源技术研究院有限公司2023年招聘公告-高校人才网

1 年前

低调的梨子 · Python 使用 JSON Diff 比较多级 JSON 对象_迹忆客

1 年前