检查包含null属性的int数组

Question

我在int []中想要检查列表中的特定属性是否存在于数组中.这是我的财产,

public class WaitingLists
    {
        [Key]
        public Int32 Id { get; set; }
        public Guid UserId { get; set; }
        public Int32 GameTableId { get; set; }
        public Int32 WaitingListTypeId { get; set; }
        **public Int32 ? StakeBuyInId { get; set; }**
    }

然后我想检查我的列表中是否存在StakeBuyInId.

这是Linq的代码,

public GameListItem[] GetMyWaitingList(Guid UserId, int[] WaitingListTypeIds, int[] StakeBuyInIds)
        {
            ProviderDB db = new ProviderDB();

            List<GameListItem> objtempGameListItem = new List<GameListItem>();

            List<GameTables> objGameTablesList = new List<GameTables>();

            var objWaitingListUser = db.WaitingLists.Where(x => x.UserId.Equals(UserId));
            if (WaitingListTypeIds != null)
            {
                objWaitingListUser = objWaitingListUser.Where(x => WaitingListTypeIds.Contains(x.WaitingListTypeId));
            }
            **if (StakeBuyInIds != null)
            {
                objWaitingListUser = objWaitingListUser.Where(x => x.StakeBuyInId != null ? StakeBuyInIds.Contains(x.StakeBuyInId) : false);
            }**
            return objtempGameListItem.ToArray();
        }

但它显示我包含不允许'int？的错误？".它只会重载'int'.所以你有任何想法如何使用linq使用Contains for null属性？谢谢你的帮助.

Answer 1

尝试

StakeBuyInIds.Contains((Int32)x.StakeBuyInId)

要么

objWaitingListUser = objWaitingListUser.Where(x => 
                 x.StakeBuyInId.HasValue  && 
                 StakeBuyInIds.Contains((Int32)x.StakeBuyInId));