Android 中 ActivityLifecycleCallbacks的实例详解

2023-09-25 07:14:05 65

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:

packagecom.cc;

importjava.util.LinkedList;

importandroid.app.Activity;
importandroid.app.Application;
importandroid.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ActivityA跳转到ActivityB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:
*1ActivityLifecycleCallbacks是在API14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
*
*/
publicclassMyApplicationextendsApplication{
privatestaticintactivityCounter=0;
privatestaticMyApplicationmApplicationInstance;
privatestaticLinkedListmActivityLinkedList;
privateActivityLifecycleCallbacksImplmActivityLifecycleCallbacksImpl;
@Override
publicvoidonCreate(){
super.onCreate();
mApplicationInstance=newMyApplication();
mActivityLinkedList=newLinkedList();
mActivityLifecycleCallbacksImpl=newActivityLifecycleCallbacksImpl();
this.registerActivityLifecycleCallbacks(mActivityLifecycleCallbacksImpl);
}

publicstaticMyApplicationgetInstance(){
if(null==mApplicationInstance){
mApplicationInstance=newMyApplication();
}
returnmApplicationInstance;
}

//判断App是否在后台运行
publicbooleanisAppRunningBackground(){
booleanflag=false;
if(activityCounter==0){
flag=true;
}
returnflag;
}

//退出应用
publicvoidfinishAllActivity(){
//unregisterActivityLifecycleCallbacks(mActivityLifecycleCallbacksImpl);
System.out.println("-->mActivityLinkedList.size()="+mActivityLinkedList.size());
if(null!=mActivityLinkedList){
for(Activityactivity:mActivityLinkedList){
if(null!=activity){
activity.finish();
}
}
}
}


privateclassActivityLifecycleCallbacksImplimplementsActivityLifecycleCallbacks{
@Override
publicvoidonActivityCreated(Activityactivity,BundlesavedInstanceState){
System.out.println("onActivityCreated-->"+activity.getClass().getName());
if(null!=mActivityLinkedList&&null!=activity){
mActivityLinkedList.addFirst(activity);
}
}

@Override
publicvoidonActivityStarted(Activityactivity){
activityCounter++;
System.out.println("onActivityStarted-->"+activity.getClass().getName()+",activityCounter="+activityCounter);
}

@Override
publicvoidonActivityResumed(Activityactivity){
System.out.println("onActivityResumed-->"+activity.getClass().getName());
}

@Override
publicvoidonActivityPaused(Activityactivity){
System.out.println("onActivityPaused-->"+activity.getClass().getName());
}

@Override
publicvoidonActivityStopped(Activityactivity){
activityCounter--;
System.out.println("onActivityStopped-->"+activity.getClass().getName()+",activityCounter="+activityCounter);
}

@Override
publicvoidonActivitySaveInstanceState(Activityactivity,BundleoutState){
System.out.println("onActivitySaveInstanceState-->"+activity.getClass().getName());
}

@Override
publicvoidonActivityDestroyed(Activityactivity){
System.out.println("onActivityDestroyed-->"+activity.getClass().getName());
if(null!=mActivityLinkedList&&null!=activity){
if(mActivityLinkedList.contains(activity)){
mActivityLinkedList.remove(activity);
}
}
}

}

}

FirstActivity如下:

packagecom.cc;

importandroid.app.Activity;
importandroid.content.Context;
importandroid.content.Intent;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;
publicclassFirstActivityextendsActivity{
privateContextmContext;
privateButtonmOpenNewActivityButton;
privateButtonmFinishThisActivityButton;
privateClickListenerImplmClickListenerImpl;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.first_activity);
init();
}

privatevoidinit(){
mContext=this;
mClickListenerImpl=newClickListenerImpl();
mOpenNewActivityButton=(Button)findViewById(R.id.openNewActivityButton);
mOpenNewActivityButton.setOnClickListener(mClickListenerImpl);
mFinishThisActivityButton=(Button)findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
}


privateclassClickListenerImplimplementsOnClickListener{
@Override
publicvoidonClick(Viewv){
switch(v.getId()){
caseR.id.openNewActivityButton:
Intentintent=newIntent(mContext,SecondActivity.class);
startActivity(intent);
break;
caseR.id.finishThisActivityButton:
finish();
break;

default:
break;
}

}

}

@Override
protectedvoidonResume(){
super.onResume();
//System.out.println("firstActivityonResume-->"+MyApplication.getInstance().isAppRunningBackground());
}

@Override
protectedvoidonStop(){
super.onStop();
//System.out.println("firstActivityonStop-->"+MyApplication.getInstance().isAppRunningBackground());
}


}

SecondActivity如下:

packagecom.cc;

importandroid.app.Activity;
importandroid.content.Context;
importandroid.content.Intent;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;

publicclassSecondActivityextendsActivity{
privateContextmContext;
privateButtonmOpenNewActivityButton;
privateButtonmFinishThisActivityButton;
privateClickListenerImplmClickListenerImpl;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.second_activity);
init();
}

privatevoidinit(){
mContext=this;
mClickListenerImpl=newClickListenerImpl();
mOpenNewActivityButton=(Button)findViewById(R.id.openNewActivityButton);
mOpenNewActivityButton.setOnClickListener(mClickListenerImpl);
mFinishThisActivityButton=(Button)findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
}


privateclassClickListenerImplimplementsOnClickListener{
@Override
publicvoidonClick(Viewv){
switch(v.getId()){
caseR.id.openNewActivityButton:
Intentintent=newIntent(mContext,ThirdActivity.class);
startActivity(intent);
break;

caseR.id.finishThisActivityButton:
finish();
break;

default:
break;
}

}

}


}

ThirdActivity如下:

packagecom.cc;

importandroid.app.Activity;
importandroid.content.Context;
importandroid.content.Intent;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;

publicclassThirdActivityextendsActivity{
privateContextmContext;
privateButtonmFinishAllActivityButton;
privateButtonmFinishThisActivityButton;
privateClickListenerImplmClickListenerImpl;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.third_activity);
init();
}

privatevoidinit(){
mContext=this;
mClickListenerImpl=newClickListenerImpl();
mFinishThisActivityButton=(Button)findViewById(R.id.finishThisActivityButton);
mFinishThisActivityButton.setOnClickListener(mClickListenerImpl);
mFinishAllActivityButton=(Button)findViewById(R.id.finishAllActivityButton);
mFinishAllActivityButton.setOnClickListener(mClickListenerImpl);
}


privateclassClickListenerImplimplementsOnClickListener{
@Override
publicvoidonClick(Viewv){
switch(v.getId()){
caseR.id.finishThisActivityButton:
finish();
break;
caseR.id.finishAllActivityButton:
MyApplication.getInstance().finishAllActivity();
break;
default:
break;
}

}
}

@Override
protectedvoidonResume(){
super.onResume();
//System.out.println("thirdActivityonResume-->"+MyApplication.getInstance().isAppRunningBackground());
}

@Override
protectedvoidonStop(){
super.onStop();
//System.out.println("thirdActivityonStop-->"+MyApplication.getInstance().isAppRunningBackground());
}

@Override
protectedvoidonDestroy(){
super.onDestroy();
//System.out.println("thirdActivityonDestroy-->"+MyApplication.getInstance().isAppRunningBackground());
}


}

first_activity.xml如下:

second_activity.xml如下:

third_activity.xml如下:

AndroidManifest.xml如下:

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Android 中 ActivityLifecycleCallbacks的实例详解

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