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" />