public boolean isForeground(String myPackage){

ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE); List< ActivityManager.RunningTaskInfo > runningTaskInfo = manager.getRunningTasks(1);      ComponentName componentInfo = runningTaskInfo.get(0).topActivity;   if(componentInfo.getPackageName().equals(myPackage)) return true;return false;}

增加permission：

<uses-permission android:name="android.permission.GET_TASKS" />