Android

Android : 监听app后台切换到前台

作者：SNS前端团队

App后台切换前台可以通过ActivityLifecycleCallbacks方法来实现，ActivityLifecycleCallbacks可以用来监听app中所有Activity的声明周期

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public void unRegister(Application application){
     application.unregisterActivityLifecycleCallbacks(activityLifecycleCallbacks);
 }

 private Application.ActivityLifecycleCallbacks activityLifecycleCallbacks = new Application.ActivityLifecycleCallbacks() {
     //打开的Activity数量统计
     private int activityStartCount = 0;
     
     @Override
     public void onActivityStarted(Activity activity) {
         activityStartCount++;
         //数值从0变到1说明是从后台切到前台
         if (activityStartCount == 1){
             //从后台切到前台
             if(mOnAppStatusListener != null){
                 mOnAppStatusListener.onFront();
             }
         }
     }

     @Override
     public void onActivityStopped(Activity activity) {
         activityStartCount--;
         //数值从1到0说明是从前台切到后台
         if (activityStartCount == 0){
             //从前台切到后台
             if(mOnAppStatusListener != null){
                 mOnAppStatusListener.onBack();
             }
         }
     }
     
 };