使用Linq 做數據去重

 #region 數據去重復

                var reslut = new List<string>(); 需要去重的數據集合
                if (!string.IsNullOrEmpty(query.First().MergeOrders))//滿足去重條件
                {
                    List<string> oldRecordList = GetOldDT(iQueryId);//去重的對比數據

                    //Linq  的 Except  方法去重                 

                    reslut = (from a in newUserRecordList
                              select a).Except
                          (from b in oldRecordList
                           select b).ToList();
                }
             reslut = reslut.Take(數量).ToList();//獲取需要的數量
                #endregion