如何使用动态列名查找重复的行？

Question

如何从具有动态列的DataTable中查找重复的行。像一个实例一样，有3列，下一个实例是4列。 下面是代码-

情况1-按颜色，材质，product_id分组的数据
情况2-数据按颜色，材料，尺寸，product_id分组

案例1-

var duplicates = (from row in dtImportedData.AsEnumerable()
                 let id = row.Field<string>("product_id")
                 let Color = row.Field<object>("Color")
                 let Material = row.Field<object>("Material")
                 group row by new { id, Color, Material } into grp
                 where grp.Count() > 1
                 select grp).ToList();

情况-2

  var duplicates = (from row in dtImportedData.AsEnumerable()
                   let id = row.Field<string>("product_id")
                   let Color = row.Field<object>("Color")
                   let Material = row.Field<object>("Material")
                   let Size = row.Field<object>("Size")
                   group row by new { id, Color, Material, Size } into grp
                   where grp.Count() > 1
                   select grp).ToList();