android_41_activity生命周期

来源：互联网发布：php 手机短信接口编辑：程序博客网时间：2024/06/05 08:40

效果:

一开始运行mainActivity输出结果如下:

点击跳转到第2个activity输出如下:

点击返回到mainActivity输出如下:

再次点击,退出应用,输出如下:

注意:此时mainActivity仍驻留内存,成为空进程,并未直正消失(因为如果立马重新启动,输出的静态整型变量的数值是接着上一次的值继续再增加)

清单文件:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.sg31.activitylifecycle"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="21" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>                        <activity android:name="com.sg31.activitylifecycle.SecondActivity"            ></activity>            </application></manifest>

mainActivity布局文件:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.sg31.activitylifecycle.MainActivity"         android:orientation="vertical"     >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="@string/hello_world" />    <Button         android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="跳转至第二个"        android:onClick="jumpBtnClicked"                />    </LinearLayout>

第2个Activity布局文件:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >        <TextView     android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="这是第二个Activity"    />    </LinearLayout>

mainActivity代码:

package com.sg31.activitylifecycle;import android.support.v7.app.ActionBarActivity;import android.content.Intent;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;public class MainActivity extends ActionBarActivity {static int i = 1;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);System.out.println("sg__mainActivity__create"+"__"+i++);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}@Overrideprotected void onStart() {super.onStart();System.out.println("sg__mainActivity__start"+"__"+i++);}@Overrideprotected void onResume() {super.onResume();System.out.println("sg__mainActivity__resume"+"__"+i++);}@Overrideprotected void onPause() {super.onPause();System.out.println("sg__mainActivity__pause"+"__"+i++);}@Overrideprotected void onStop() {super.onStop();System.out.println("sg__mainActivity__stop"+"__"+i++);}@Overrideprotected void onDestroy() {super.onDestroy();System.out.println("sg__mainActivity__destroy"+"__"+i++);}@Overrideprotected void onRestart() {super.onRestart();System.out.println("sg__mainActivity__restart"+"__"+i++);}public void jumpBtnClicked(View v) {Intent intent = new Intent(this, SecondActivity.class);startActivity(intent);}}

第2个Activity代码:

package com.sg31.activitylifecycle;import android.os.Bundle;import android.support.v7.app.ActionBarActivity;public class SecondActivity extends ActionBarActivity {static int i = 1;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_second);System.out.println("sg__secondActivity__create"+"______"+i++);}@Overrideprotected void onStart() {super.onStart();System.out.println("sg__secondActivity__start"+"______"+i++);}@Overrideprotected void onResume() {super.onResume();System.out.println("sg__secondActivity__resume"+"______"+i++);}@Overrideprotected void onPause() {super.onPause();System.out.println("sg__secondActivity__pause"+"______"+i++);}@Overrideprotected void onStop() {super.onStop();System.out.println("sg__secondActivity__stop"+"______"+i++);}@Overrideprotected void onDestroy() {super.onDestroy();System.out.println("sg__secondActivity__destroy"+"______"+i++);}@Overrideprotected void onRestart() {super.onRestart();System.out.println("sg__secondActivity__restart"+"______"+i++);}}

0 0