flutter PageView设置无限滚动

PageView.builder(
      controller: _pageController,
        pageSnapping: true,
        onPageChanged: (index){
          setState(() {
            _pageIndex = index;
          });
        },
        itemCount: widget.bannerList.length * 10000,//设置一个很大的count
        itemBuilder: (_, index){
      return _itemView(index % (widget.bannerList.length)); //利用下标与数据源长度取余重复构建视图
    });