============问题描述============
我在一个Acitivity里面写了多个Fragment.。有好几层的fragment在跳转，但是我一按手机上的回退键就把当前的Activity关掉了，也就是fragment全部都被关掉了。我想实现当按回退的时候返回到上一个fragment。。请问能否实现？该如何实现？
============解决方案1============
Before you call commit(), however, you might want to call addToBackStack(), in order to add the transaction to a back stack of fragment transactions. This back stack is managed by the activity and allows the user to return to the previous fragment state, by pressing the Back button.求android老手指导。。
原文：http://www.cnblogs.com/llj1985522/p/4033853.html
