DataSet 删除数据 不更新数据库

string SelectCommand = string.Format("select top 1 Id, PiaoJuPiaoHao, DaoZhanDianMian, HuoWuPinMing, JianShu, ZhongLiang, TiJi, ZhuangTai, FaZhanDianMian, CheChi from FaZhanPiaoJuBiao");//定义数据样式
        bool flag = false;

        for (int i = GridView1.Rows.Count-1; i <= GridView1.Rows.Count-1; i--)//从下向上遍历
        {
          CheckBox box =  GridView1.Rows[i].FindControl("CheckBox1") as CheckBox;
          flag = box.Checked;
          if (flag == true)
          {
              dt.Tables[0].Rows.RemoveAt(GridView1.Rows[i].RowIndex);
              //dt.AcceptChanges();   
          }
          if (i == 0)
          {
              break;
          }
        }
 
       GridView1.DataSource = dt.Tables[0];

              GridView1.DataBind();

 

为什么 从下向上遍历呢  因为 数据集再循环中 删除一条语句 其他的索引下标就随着改变 所以 从下向上遍历