Activity和Fragment生命周期

Activity和Fragment生命周期的关系如下面的。主要是通过log了解他们的生命周期。我们通常很多事情都是直接在onCreate里面做了。但是其实有的事情是应该在其他的

步骤完成。目前我使用到的是更新UI及数据的操作应该在onStart里面做。因为跳到其他界面进行编辑后返回原来的界面时

往往会对UI进行更新，这时候需要在onStart里面跟新一下。下面对照这个图。写了一个简单的程序。有三个Fragment ：FirstFragment，SecondFragment，ThirdFragment，分别依附这三个activity：FirstActivty，SecondActivity，ThirdActivity。其中FirstFragment两个按钮分别可以跳到SecondActivity和ThirdActivity。ThirdActivity是一个对话框(在AndroidManifest.xml里面可以设置)。

   


启动FirstActivity  --> 启动SecondActivity ---> 返回FirstActivity ---> 退出FirstActivty 的log

//启动FirstActvity

08-04 16:24:48.816: I/DBG(966): FirstActivity-> onCreate

08-04 16:24:48.817: I/DBG(966): FirstFragment-> onAttach

08-04 16:24:48.818: I/DBG(966): FirstFragment-> onCreate

08-04 16:24:48.818: I/DBG(966): FirstFragment-> onCreateView

08-04 16:24:48.823: I/DBG(966): FirstFragment-> onActivityCreated

08-04 16:24:48.824: I/DBG(966): FirstFragment-> onStart

08-04 16:24:48.824: I/DBG(966): FirstActivity-> onStart

08-04 16:24:48.825: I/DBG(966): FirstActivity-> onResume

08-04 16:24:48.825: I/DBG(966): FirstFragment-> onResume

//按键启动了SecondActvity

08-04 16:24:49.759: I/DBG(966): FirstFragment-> onPause

08-04 16:24:49.759: I/DBG(966): FirstActivity-> onPause

08-04 16:24:49.794: I/DBG(966): SecondActivity-> onCreate

08-04 16:24:49.795: I/DBG(966): SecondFragment-> onAttach

08-04 16:24:49.795: I/DBG(966): SecondFragment-> onCreate

08-04 16:24:49.796: I/DBG(966): SecondFragment-> onCreateView

08-04 16:24:49.799: I/DBG(966): SecondFragment-> onActivityCreated

08-04 16:24:49.799: I/DBG(966): SecondFragment-> onStart

08-04 16:24:49.799: I/DBG(966): SecondActivity-> onStart

08-04 16:24:49.800: I/DBG(966): SecondActivity-> onResume

08-04 16:24:49.801: I/DBG(966): SecondFragment-> onResume

08-04 16:24:50.086: I/DBG(966): FirstFragment-> onStop

08-04 16:24:50.087: I/DBG(966): FirstActivity-> onStop

//按取消键返回到FirstActvity,所以一些刷新显示的动作应该在onstart里面执行

08-04 16:24:51.208: I/DBG(966): SecondFragment-> onPause

08-04 16:24:51.209: I/DBG(966): SecondActivity-> onPause

08-04 16:24:51.214: I/DBG(966): FirstActivity-> onRestart

08-04 16:24:51.215: I/DBG(966): FirstFragment-> onStart

08-04 16:24:51.215: I/DBG(966): FirstActivity-> onStart

08-04 16:24:51.216: I/DBG(966): FirstActivity-> onResume

08-04 16:24:51.216: I/DBG(966): FirstFragment-> onResume

08-04 16:24:51.478: I/DBG(966): SecondFragment-> onStop

08-04 16:24:51.479: I/DBG(966): SecondActivity-> onStop

08-04 16:24:51.480: I/DBG(966): SecondFragment-> onDestroyView

08-04 16:24:51.482: I/DBG(966): SecondFragment-> onDestroy

08-04 16:24:51.483: I/DBG(966): SecondFragment-> onDetach

08-04 16:24:51.484: I/DBG(966): SecondActivity-> onDestroy

//按取消键退出FirstActvity

08-04 16:24:52.836: I/DBG(966): FirstFragment-> onPause

08-04 16:24:52.837: I/DBG(966): FirstActivity-> onPause

08-04 16:24:53.124: I/DBG(966): FirstFragment-> onStop

08-04 16:24:53.127: I/DBG(966): FirstActivity-> onStop

08-04 16:24:53.127: I/DBG(966): FirstFragment-> onDestroyView

08-04 16:24:53.128: I/DBG(966): FirstFragment-> onDestroy

08-04 16:24:53.129: I/DBG(966): FirstFragment-> onDetach

08-04 16:24:53.129: I/DBG(966): FirstActivity-> onDestroy

启动FirstActivity  --> 启动ThirdActivity ---> 返回FirstActivity ---> 退出FirstActivty 的log

 

代码点击这里下载：