GetX + Flutter:在更新实体内的列表时如何使Obx重建(以及通常情况下，是什么触发了Obx重建)？

class MyController extends GetxController {
  RxList<String> myList = <String>[].obs;
  
  void addItem(String item) {
    myList.add(item);
  }
}

class MyPage extends StatelessWidget {
  final MyController controller = Get.put(MyController());

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Page'),
      ),
      body: Obx(() => ListView.builder(
        itemCount: controller.myList.length,
        itemBuilder: (context, index) {
          return ListTile(
            title: Text(controller.myList[index]),
          );
        },
      )),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          controller.addItem('New Item');
        },
        child: Icon(Icons.add),
      ),
    );
  }
}