C# 操作datatable校验重复行，并显示行号

 　　　　　　DataColumn idColumn = new DataColumn();
                idColumn.DataType = System.Type.GetType("System.Int32");//该列的数据类型 
                idColumn.ColumnName = "row_id ";
                tableRepeat.Columns.Add(idColumn);
                if (tableRepeat != null && tableRepeat.Rows.Count > 0)
                {
                    int line = 3;
                    foreach (DataRow dr in tableRepeat.Rows)
                    {
                        dr[columnCount] = line;
                        line = line + 1;
                    }
                }

       //校验手机号
            var query_mobile = from f in tableParam.AsEnumerable()
                               group f by f.Field<string>("手机号") into m
                               where m.Count() > 1
                               select m.Key;
            if (query_mobile.Any())
            {
                foreach (var item in query_mobile.ToList())
                {
                    List<int> query_row = tableParam.AsEnumerable().AsParallel().Where(m => m.Field<string>("手机号") == item.Trim()).Select<DataRow, int>(dr => int.Parse(dr[tableParam.Columns.Count - 1].ToString())).ToList();
                    if (query_row.Any())
                    {
                        var msg = $"第{string.Join("、", query_row.Take(5).OrderBy(m => m))}行{(query_row.Count >= 5 ? "等共" + query_row.Count + "行" : "")}{ErrorExpandEnum.手机号重复.ToString()}，请检查";
                        return msg;
                    }
                }
            }