Android 中 ActivityLifecycleCallbacks的实例详解
以上就是使用ActivityLifecycleCallbacks的实例，代码注释写的很清楚大家可以参考下，
MyApplication如下:
package com.cc;
import java.util.LinkedList;
import android.app.Activity;
import android.app.Application;
import android.os.Bundle;
/** * Demo示例: * ActivityLifecycleCallbacks使用示例 * * ActivityLifecycleCallbacks用于对应用中Activity的生命周期的追踪和回调 * * 使用ActivityLifecycleCallbacks可实现: * 1 判断App是否在后台运行 * 2 关闭该应用所有Activity * * * (1)判断App是否在后台运行 * 在该实现中采用activityCounter记录Activity的个数. * 通过对于activityCounter是否为0判断当前APP是否在前台运行. * * 从ActivityLifecycleCallbacks的实现方法中我们的惯性思维是: * 在ActivityLifecycleCallbacks的onActivityResumed()中activityCounter+1. * 在onActivityPaused()中activityCounter-1, * 但是这么对么？ * * 先看一下界面跳转时两个Activity的生命周期 * 当从Activity A跳转到Activity B时,两个Activity的生命周期如下: * A.onPause()->B.onCreate()->B.onStart()-> B.onResume()-> A.onStop() * * 假若按照上述方式那么: * 在A启动后activityCounter=1;
* 当从A跳转到B时在调用A.onPause()时执行:activityCounter-1=0;
* 即该APP运行在后台. * 这当然是错的,两个界面切换的过程中APP当然是运行在前台的。 * * 如下修改: * 在onActivityStarted()中对于activityCounter+1 * 在onActivityStopped()中对于activityCounter-1 * 小结:注意Activity跳转时的生命周期 * * (2)关闭该应用所有Activity * 2.1 利用LinkedList<Activity>管理应用中的界面 * 2.2 在ActivityLifecycleCallbacks的onActivityCreated() * 将Activity添加到LinkedList中 * 在ActivityLifecycleCallbacks的onActivityDestroyed() * 将Activity从LinkedList中移除 * 2.3 关闭应用时销毁LinkedList中所有Activity * * 备注说明: * 1 ActivityLifecycleCallbacks是在API 14及其以上才有的 * 2 在Android4.0以下可以在BaseActivity中按照该思路实现 * */ public class MyApplication extends Application {
private static int activityCounter=0;
private static MyApplication mApplicationInstance;
private static LinkedList<Activity> mActivityLinkedList;
private ActivityLifecycleCallbacksImpl mActivityLifecycleCallbacksImpl;
@Override public void onCreate() {
super.onCreate();
mApplicationInstance=new MyApplication();
mActivityLinkedList=new LinkedList<Activity>();
mActivityLifecycleCallbacksImpl=new ActivityLifecycleCallbacksImpl();
this.registerActivityLifecycleCallbacks(mActivityLifecycleCallbacksImpl);
}
public static MyApplication getInstance() {
if (null==mApplicationInstance) {
mApplicationInstance=new MyApplication();
}
return mApplicationInstance;
}
//判断App是否在后台运行 public boolean isAppRunningBackground(){
boolean flag=false;
if(activityCounter==0){
flag=true;
}
return flag;
}
//退出应用 public void finishAllActivity(){
//unregisterActivityLifecycleCallbacks(mActivityLifecycleCallbacksImpl);
System.out.println("--> mActivityLinkedList.size()="+mActivityLinkedList.size());
if(null!=mActivityLinkedList){
for(Activity activity:mActivityLinkedList){
if(null!=activity){
activity.finish();
}
}
}
}
private class ActivityLifecycleCallbacksImpl implements ActivityLifecycleCallbacks{
@Override public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
System.out.println("onActivityCreated --> "+activity.getClass().getName());
if (null!=mActivityLinkedList&&null!=activity) {
mActivityLinkedList.addFirst(activity);
}
}
@Override public void onActivityStarted(Activity activity) {
activityCounter++;
System.out.println("onActivityStarted --> "+activity.getClass().getName()+",activityCounter="+activityCounter);
}
@Override public void onActivityResumed(Activity activity) {
System.out.println("onActivityResumed --> "+activity.getClass().getName());
}
@Override public void onActivityPaused(Activity activity) {
System.out.println("onActivityPaused --> "+activity.getClass().getName());
}
@Override public void onActivityStopped(Activity activity) {
activityCounter--;
System.out.println("onActivityStopped --> "+activity.getClass().getName()+",activityCounter="+activityCounter);
}
@Override public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
System.out.println("onActivitySaveInstanceState --> "+activity.getClass().getName());
}
@Override public void onActivityDestroyed(Activity activity) {
System.out.println("onActivityDestroyed --> "+activity.getClass().getName());
if (null!=mActivityLinkedList&&null!=activity) {
if (mActivityLinkedList.contains(activity)) {
mActivityLinkedList.remove(activity);
}
}
}
}
}
FirstActivity如下:
package com.cc;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class FirstActivity extends Activity {
private Context mContext;
private Button mOpenNewActivityButton;
private Button mFinishThisActivityButton;
private ClickListenerImpl mClickListenerImpl;
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_activity);
init();
}
private void init(){
mContext=this;
mClickListenerImpl=new ClickListenerImpl();
mOpenNewActivityButton=(Button) findViewById(R.id.openNewActivityButton);
mOpenNewActivityButton.setOnClickListener(mClickListenerImpl);
mFinishThisActivityButton=(Button) findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
}
private class ClickListenerImpl implements OnClickListener {
@Override public void onClick(View v) {
switch (v.getId()) {
case R.id.openNewActivityButton: Intent intent=new Intent(mContext, SecondActivity.class);
startActivity(intent);
break;
case R.id.finishThisActivityButton: finish();
break;
default: break;
}
}
}
@Override protected void onResume() {
super.onResume();
//System.out.println(" first Activity onResume --> "+MyApplication.getInstance().isAppRunningBackground());
}
@Override protected void onStop() {
super.onStop();
//System.out.println(" first Activity onStop --> "+MyApplication.getInstance().isAppRunningBackground());
}
}
SecondActivity如下:
package com.cc;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class SecondActivity extends Activity {
private Context mContext;
private Button mOpenNewActivityButton;
private Button mFinishThisActivityButton;
private ClickListenerImpl mClickListenerImpl;
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second_activity);
init();
}
private void init(){
mContext=this;
mClickListenerImpl=new ClickListenerImpl();
mOpenNewActivityButton=(Button) findViewById(R.id.openNewActivityButton);
mOpenNewActivityButton.setOnClickListener(mClickListenerImpl);
mFinishThisActivityButton=(Button) findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
}
private class ClickListenerImpl implements OnClickListener {
@Override public void onClick(View v) {
switch (v.getId()) {
case R.id.openNewActivityButton: Intent intent=new Intent(mContext, ThirdActivity.class);
startActivity(intent);
break;
case R.id.finishThisActivityButton: finish();
break;
default: break;
}
}
}
}
ThirdActivity如下:
package com.cc;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class ThirdActivity extends Activity {
private Context mContext;
private Button mFinishAllActivityButton;
private Button mFinishThisActivityButton;
private ClickListenerImpl mClickListenerImpl;
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.third_activity);
init();
}
private void init(){
mContext=this;
mClickListenerImpl=new ClickListenerImpl();
mFinishThisActivityButton=(Button) findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
mFinishAllActivityButton=(Button) findViewById(R.id.finishAllActivityButton);
mFinishAllActivityButton.setOnClickListener(mClickListenerImpl);
}
private class ClickListenerImpl implements OnClickListener {
@Override public void onClick(View v) {
switch (v.getId()) {
case R.id.finishThisActivityButton: finish();
break;
case R.id.finishAllActivityButton: MyApplication.getInstance().finishAllActivity();
break;
default: break;
}
}
}
@Override protected void onResume() {
super.onResume();
//System.out.println(" third Activity onResume --> "+MyApplication.getInstance().isAppRunningBackground());
}
@Override protected void onStop() {
super.onStop();
//System.out.println(" third Activity onStop --> "+MyApplication.getInstance().isAppRunningBackground());
}
@Override protected void onDestroy() {
super.onDestroy();
//System.out.println(" third Activity onDestroy --> "+MyApplication.getInstance().isAppRunningBackground());
}
}
first_activity.xml如下:
<RelativeLayout 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.cc.FirstActivity" > <Button android:id="@+id/openNewActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:text="open new Activity" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@id/openNewActivityButton" android:layout_centerInParent="true" android:layout_marginBottom="50dip" android:textSize="20sp" android:textColor="@android:color/holo_red_light" android:text="This is the first Activity" /> <Button android:id="@+id/finishThisActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/openNewActivityButton" android:layout_centerHorizontal="true" android:layout_marginTop="50dip" android:text="finish this activity" /> </RelativeLayout>
second_activity.xml如下:
<RelativeLayout 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.cc.FirstActivity" > <Button android:id="@+id/openNewActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:text="open new Activity" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@id/openNewActivityButton" android:layout_centerInParent="true" android:layout_marginBottom="50dip" android:textSize="20sp" android:textColor="@android:color/holo_red_light" android:text="This is the second Activity" /> <Button android:id="@+id/finishThisActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/openNewActivityButton" android:layout_centerHorizontal="true" android:layout_marginTop="50dip" android:text="finish this activity" /> </RelativeLayout>
third_activity.xml如下:
<RelativeLayout 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.cc.FirstActivity" > <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@id/openNewActivityButton" android:layout_centerHorizontal="true" android:layout_marginTop="100dp" android:text="This is the third Activity" android:textColor="@android:color/holo_red_light" android:textSize="20sp" /> <Button android:id="@+id/finishThisActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/textView" android:layout_centerHorizontal="true" android:layout_marginTop="50dip" android:text="finish this activity" /> <Button android:id="@+id/finishAllActivityButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/finishThisActivityButton" android:layout_centerHorizontal="true" android:layout_marginTop="50dip" android:text="finish All Activity" /> </RelativeLayout>
AndroidManifest.xml如下:
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.cc" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="14" /> <application android:name="com.cc.MyApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".FirstActivity" 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.cc.SecondActivity"/> <activity android:name="com.cc.ThirdActivity"/> </application> </manifest>
如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
