ActivityLifeDemo

这类文章在网上实在是多。无论是原创还是转载。本来不想写的了。就当是自己复习吧。 先看下图： 新建工程，编写如下代码： package com.android.ttx.actiitylifedemo; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.KeyEvent; public class ActivityLifeDemo extends Activity { private final static String TAG="ActivityLifeDemo"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Log.i(TAG, "onCreate"); } @Override protected void onStart() { // TODO Auto-generated method stub Log.i(TAG, "onStart"); super.onStart(); } @Override protected void onRestart() { // TODO Auto-generated method stub Log.i(TAG, "onRestart"); super.onRestart(); } @Override protected void onResume() { // TODO Auto-generated method stub Log.i(TAG, "onResume"); super.onResume(); } @Override protected void onPause() { // TODO Auto-generated method stub Log.i(TAG, "onPause"); super.onPause(); } @Override protected void onStop() { // TODO Auto-generated method stub Log.i(TAG, "onStop"); super.onStop(); } @Override protected void onDestroy() { Log.i(TAG, "onDestroy"); super.onDestroy(); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { switch (keyCode) { case KeyEvent.KEYCODE_BACK: Log.i(TAG, "按下了：KEYCODE_BACK"); break; case KeyEvent.KEYCODE_HOME: Log.i(TAG, "按下了：KEYCODE_HOME"); break; default: break; } return super.onKeyDown(keyCode, event); } } 1、运行 看到如下打印日志： 08-31 08:46:53.916: INFO/ActivityLifeDemo(312): onCreate 08-31 08:46:53.916: INFO/ActivityLifeDemo(312): onStart 08-31 08:46:53.916: INFO/ActivityLifeDemo(312): onResume 2、按下返回按键： 08-31 09:29:57.231: INFO/ActivityLifeDemo(354): 按下了：KEYCODE_BACK 08-31 09:29:57.396: INFO/ActivityLifeDemo(354): onPause 08-31 09:29:58.216: INFO/ActivityLifeDemo(354): onStop 08-31 09:29:58.216: INFO/ActivityLifeDemo(354): onDestroy 3、长按Home键，弹出最近打开过的应用程序，点击ActivityLifeDemo 08-31 08:51:46.916: INFO/ActivityLifeDemo(312): onCreate 08-31 08:51:46.916: INFO/ActivityLifeDemo(312): onStart 08-31 08:51:46.936: INFO/ActivityLifeDemo(312): onResume 4、按Home键 08-31 08:53:32.676: INFO/ActivityLifeDemo(312): onPause 08-31 08:53:33.796: INFO/ActivityLifeDemo(312): onStop 5、在AllList中点击打开 08-31 08:54:14.286: INFO/ActivityLifeDemo(312): onRestart 08-31 08:54:14.286: INFO/ActivityLifeDemo(312): onStart 08-31 08:54:14.296: INFO/ActivityLifeDemo(312): onResume 通过打印日志信息，得出如下结论：按返回键时应用程序结束了生命周期，调用onDestroy方法；按Home键时只是暂停，调用onStop方法，在再次打开应用程序时会调用onRestart重写启动应用程序。