protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(string));
            for (int i = 0; i < 10; i++)
            {
                dt.Rows.Add(i.ToString());
            }
            Cache["Table"] = dt;
        }
        else
        {
            DataTable dt = Cache["Table"] as DataTable;
            dt.Rows[2]["Id"] = "这是我修过过的ID";
            //重新保存到cache中
            Cache["Table"] = dt;
        }
    }