private static void changeFragment(Fragment f, boolean init) {
        FragmentTransaction ft = fm.beginTransaction();
        ft.replace(R.id.info_content, f,f.getClass().getName());
        if(!init){
            ft.addToBackStack(null);
        }
        ft.commit();
    }

当我想要得到的协议栈通过调用fm.getBackStackEntryCount（COUT），它返回零？

when I want to get the stack cout by call fm.getBackStackEntryCount(), it returns zero?

推荐答案

您得叫 fm.executePendingTransactions（）在 ft.commit （）或之前 fm.getBackStackEntryCount（）。由于提交（）只时间表以后通的交易。

You have to call a fm.executePendingTransactions() after ft.commit() or before fm.getBackStackEntryCount(). Because the commit() only schedules the transactions for a later pass.