状态恢复 (State Restoration) 与 Engine 生命周期同步：Android 进程被杀后无缝自愈

## 1. 为什么移动端需要状态恢复？ 在低内存 Android 设备上，App 切入后台很容易被 LMK (Low Memory Killer) 静默终止。当用户重新打开 App 时，如果状态丢失会带来极差的体验。 ## 2. RestorationMixin 实战 Flutter 提供了框架级状态序列化支持： ```dart class _MyFormState extends State<MyForm> with RestorationMixin { final RestorableTextEditingController _controller = RestorableTextEditingController(); @override String? get restorationId => my_form_restoration_id; @override void restoreState(RestorationBucket? oldBucket, bool initialRestore) { registerForRestoration(_controller, form_text); } } ```