文中错别字

[wumingXL]

markNeedsBuild内部，则是通过标记element为diry。应该是dirty。
flutter中的变量名字为_dirty

/// Returns true if the element has been marked as needing rebuilding.
bool get dirty => _dirty;
bool _dirty = true;

[wumingXL]

Flutter布局详解文章中

[Loki]

多谢反馈