緣由 Get Exception below: Looking up a deactivated widget's ancestor is unsafe. Solution: To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method. Question: 有沒有 Linter 的規則可以幫忙檢查？

職責（What） Widget Tree：UI 藍圖、設定檔 Element Tree：UI 生命週期的管理 RenderObject Tree：UI 佈局與繪製 相互關係（Why & How） 性能優化 Declarative(陳述式) vs Imperative(命令式) Imperative：

Preview: Two-dimensional scrolling in Flutter note: What is "Two-dimensional scrolling" Why "Preview:" -> Coming soon in a future release of Flutter youtube Outline Video Introduction 即時市況與排行 Table