android fragment切换无法保存状态的一种解决方法

通过显示隐藏来处理：             int tabIndex=0,tag=0;             fragment[] fragments=new fragment[]{A.class,B.class,C.class,D.class};             Fragment newFragment = fragments[tag];             FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();             if (!getSupportFragmentManager().getFragments().contains(fragments[tag])) {                 transaction.add(R.id.main_content, newFragment);             }              transaction.addToBackStack(null);                          transaction.hide(fragments[tabIndex]);             transaction.show(newFragment);                transaction.commit();             tabIndex = tag;