Fragment必须是依存于Activity而存在的，因此Activity的生命周期会直接影响到Fragment的生命周期。官网这张图很好的说明了俩者的关系：
可以看到Fragment比Activity多了几个额外的生命周期回调函数：
onAttach(Activity);//当Activity与Fragment发生关联时调用 onCreateView(LayoutInflater,ViewGroup,Bundle);//创建该Fragment的视图 onActivityCreate(bundle);//当Activity的onCreate()；方法返回时调用 onDestoryView();//与onCreateView相对应，当改Fragment被移除时调用 onDetach();//与onAttach()相对应，当Fragment与Activity的关联被取消时调用
注意：除了onCreateView，其他的所有方法如果你重写了，必须调用父类对于该方法的实现。
场景演示 :
切换到该Fragment
11-29 14:26:35.095: D/AppListFragment(7649): onAttach 11-29 14:26:35.095: D/AppListFragment(7649): onCreate 11-29 14:26:35.095: D/AppListFragment(7649): onCreateView 11-29 14:26:35.100: D/AppListFragment(7649): onActivityCreated 11-29 14:26:35.120: D/AppListFragment(7649): onStart 11-29 14:26:35.120: D/AppListFragment(7649): onResume
屏幕灭掉：
11-29 14:27:35.185: D/AppListFragment(7649): onPause 11-29 14:27:35.205: D/AppListFragment(7649): onSaveInstanceState 11-29 14:27:35.205: D/AppListFragment(7649): onStop
屏幕解锁
11-29 14:33:13.240: D/AppListFragment(7649): onStart 11-29 14:33:13.275: D/AppListFragment(7649): onResume
切换到其他Fragment:
11-29 14:33:33.655: D/AppListFragment(7649): onPause 11-29 14:33:33.655: D/AppListFragment(7649): onStop 11-29 14:33:33.660: D/AppListFragment(7649): onDestroyView
切换回本身的Fragment:
11-29 14:33:55.820: D/AppListFragment(7649): onCreateView 11-29 14:33:55.825: D/AppListFragment(7649): onActivityCreated 11-29 14:33:55.825: D/AppListFragment(7649): onStart 11-29 14:33:55.825: D/AppListFragment(7649): onResume
回到桌面
11-29 14:34:26.590: D/AppListFragment(7649): onPause 11-29 14:34:26.880: D/AppListFragment(7649): onSaveInstanceState 11-29 14:34:26.880: D/AppListFragment(7649): onStop
回到应用
11-29 14:36:51.940: D/AppListFragment(7649): onStart 11-29 14:36:51.940: D/AppListFragment(7649): onResume
退出应用
11-29 14:37:03.020: D/AppListFragment(7649): onPause 11-29 14:37:03.155: D/AppListFragment(7649): onStop 11-29 14:37:03.155: D/AppListFragment(7649): onDestroyView 11-29 14:37:03.165: D/AppListFragment(7649): onDestroy 11-29 14:37:03.165: D/AppListFragment(7649): onDetach
比Activity多了一些生命周期，完整和Activity对接上，大家好好利用。