[4.18]Android生命周期介绍

抄着敲着

#1 Activity：

Activity是一个交互界面，可以布满整个窗口，或者悬浮于其他窗口上

一个程序由多个Activity组成，Manifest中指明了主Activity

<activity <span style="white-space:pre"></span>android:label="@string/app_name"<span style="white-space:pre"></span>android:name=".MainActivity" >  <intent-filter > <span style="white-space:pre"></span><action android:name="android.intent.action.MAIN" /> <span style="white-space:pre"></span><category android:name="android.intent.category.LAUNCHER" />   </intent-filter></activity>

Activity是一个互相调用关系，以栈的形式存取

#2 生命周期

voidonCreate(BundlesavedInstanceState) 
voidonStart() 
voidonRestart() 
voidonResume() 
voidonPause() 
voidonStop() 
voidonDestroy()

开始Activity：onCreate、onStart和onResume方法。
Activity失去焦点：onPause、onStop
Activity重新获得焦点：onRestart、onStart和onResume
关闭Activity：onPause、onStop和onDestory

#3 测试代码

package com.android.mylife;import android.app.Activity;import android.os.Bundle;import android.util.Log;public class Main extends Activity {/** Called when the activity is first created. */private final String TAG = "Main";@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Log.i(TAG, "onCreate Method is executed");}@Overrideprotected void onStart() {// TODO Auto-generated method stubsuper.onStart();Log.i(TAG, "onStart Method is executed");}@Overrideprotected void onRestart() {// TODO Auto-generated method stubsuper.onRestart();Log.i(TAG, "onRestart Method is executed");}@Overrideprotected void onResume() {// TODO Auto-generated method stubsuper.onResume();Log.i(TAG, "onResume Method is executed");}@Overrideprotected void onStop() {// TODO Auto-generated method stubsuper.onStop();Log.i(TAG, "onStop Method is executed");}@Overrideprotected void onPause() {// TODO Auto-generated method stubsuper.onPause();Log.i(TAG, "onPause Method is executed");}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();Log.i(TAG, "onDestroy Method is executed");}}