我想这个小部件（TabButton）改变其状态，并运行isSelected func ever currentPageIndex值在控制器中的变化。
我的小部件：

Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Obx(
            () => TabButton(
              title: 'AGORA',
              onPress: () => widget.pageController.jumpToPage(0),
              isSelected: _controller.isSelected(0),
            ),
          ),
          Obx(
            () => TabButton(
              title: 'AGENDA',
              onPress: () => widget.pageController.jumpToPage(1),
              isSelected: _controller.isSelected(1),
            ),
          ),
          Obx(
            () => TabButton(
              title: 'FAVORITOS',
              onPress: () => widget.pageController.jumpToPage(2),
              isSelected: _controller.isSelected(2),
            ),
          ),
        ],
      ),

我的控制器：

class RootScreenController extends GetxController {
  Rx<int> currentPageIndex = 1.obs;

  // It's called in PageView
  void pageChangged(int index) {
    currentPageIndex.value = index;
  }

  bool isSelected(int buttonIndex){
    return currentPageIndex.value == buttonIndex;
  }
}

我不知道我做错了什么，但按钮的状态没有改变。