LIst去重，重写方法，继承接口。

调用： 
 var dataThis = data.Where(es=>es.IndentyTime== identyDateList[0]).ToList();
            var dic = dataThis.Distinct( new repDic()).ToList();var repList = "";
            foreach (var item in dic)
            {
                if (repList == "") repList = item.RepID.ToString();
                else repList += ","+item.RepID.ToString();
            }

去重方法：     
 public class repDic : IEqualityComparer<Ta_GoodsValue>
        {
            public bool Equals(Ta_GoodsValue x,Ta_GoodsValue y)
            {
                return x.RepID == y.RepID;
            }

            public int GetHashCode(Ta_GoodsValue x)
            {
                return x.ToString().GetHashCode();
            }
        }