在android 5.0以上，如何判断当前应用是在前台还是后台

今天在做项目时遇到这个问题，本来很简单的，但是在android 5.1 的系统上运行却出错了，在网上查找答案后发现原来是在android 5.0 之后getRunningTask（）方法被废弃，失效了。在网上查到的解决方法如下，已验证有效：

 private boolean isAppIsInBackground(Context context) {
        boolean isInBackground = true;
        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {
            List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();
            for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {
                //前台程序
                if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                    for (String activeProcess : processInfo.pkgList) {
                        if (activeProcess.equals(context.getPackageName())) {
                            isInBackground = false;
                        }
                    }
                }
            }
        } else {
            List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
            ComponentName componentInfo = taskInfo.get(0).topActivity;
            if (componentInfo.getPackageName().equals(context.getPackageName())) {
                isInBackground = false;
            }
        }

        return isInBackground;
    }