这篇文章主要介绍了Android 中 ActivityLifecycleCallbacks的实例详解的相关资料,希望通过本文大家能掌握这部分内容，需要的朋友可以参考下

MyApplication代码如下:

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); 
        } 
      } 
    } 
     
  } 
 
} 

小结

可以使用ActivityLifecycleCallbacks实现两个功能
1.判断app、activity是否在前台
onStart/onStop去做累加和减法
2.销毁所有的activity
onCreate/onDestroy做记录和销毁