Flutter嵌套PageView处理工具

    return NestPageHelperParent(
        child: PageView.builder(
            itemCount: 5,
            controller: pageController,
            itemBuilder: (context, index) {
              //嵌套PageView
              if (index == 3)
                return NestPageHelperChild(
                    child: PageView.builder(
                        itemCount: 5,
                        itemBuilder: (_, index) {
                          return Center(
                            child: Text("内部" + index.toString()),
                          );
                        }));
              return Center(
                child: Text(index.toString()),
              );
            }),
        pageController: pageController);