Android 程序是否是在前端运行

/** * 程序是否在前台运行 * * @return */public boolean isAppOnForeground() {    ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);    String packageName = getApplicationContext().getPackageName();    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager            .getRunningAppProcesses();    if (appProcesses == null)        return false;    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {        // The name of the process that this object is associated with.        if (appProcess.processName.equals(packageName)                && appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {            return true;        }    }    return false;}