public static bool DeleteMessages(int messageId, string operUser, out string errmsg)
        {
            errmsg = "";
            using (var client = new PushClient())
            {
                var pushResult = client.DeletePushMessage(messageId, operUser);

                if (pushResult != null && pushResult.Result == 1)
                {
                    return(true);
                }
                //异常
                if (pushResult == null || pushResult.ErrorCode == "98")
                {
                    logger.Log(Level.Error, pushResult.ErrorMessage, "Error occurred in PushTaskMessage");
                }

                switch (pushResult.Result)
                {
                case 2:
                    errmsg = "删除失败!超出发送时间不能删除";
                    break;

                case 3:
                    errmsg = "删除失败!只有新建的推送消息才可以删除";
                    break;

                case 4:
                    errmsg = "消息已经推送,不能删除";
                    break;

                default:
                    errmsg = "删除失败!";
                    break;
                }
                return(false);
            }
        }