/// <summary>
 /// 指定时间阈值可用座位数
 /// </summary>
 /// <param name="room">自习室编号</param>
 /// <param name="time">时间阈值</param>
 /// <param name="now">当前时间</param>
 /// <returns>座位数</returns>
 public int SetRedundancy(int room, int time, DateTime now)
 {
     return(SqlServerHelper.ExeProc_GetRedundancyAfter(room, now.AddMinutes(time)));
 }