頁面跳轉代碼寫在setState方法里面無效
bottomNavigationBar:?BottomNavigationBar(
??type:?BottomNavigationBarType.fixed,
??currentIndex:?_currentIndex,
??onTap:?(index)?{
????setState(()?{
??????_contentPagerController.jumpToPage(index);
??????_currentIndex?=?index;
????});
??},為什么 _contentPagerController.jumpToPage(index); 必須要寫在setState方法外面，?寫在里就變得無效了呢
