can not run correctly, get a exception,

[yunnywu]

flutter: ══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════
flutter: The following assertion was thrown while dispatching notifications for FocusNode:
flutter: RenderBox was not laid out: RenderEditable#a34bb NEEDS-LAYOUT NEEDS-PAINT
flutter: 'package:flutter/src/rendering/box.dart':
flutter: Failed assertion: line 1687 pos 12: 'hasSize'