protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowState.ToString().IndexOf("Edit") != -1)
        {
            //Response.Write("<br>" + e.Row.RowIndex.ToString() + "：" + e.Row.RowState.ToString());
            //Response.Write("<br>总行数：" + GridView1.Rows.Count.ToString());
            //Alternate, Edit或者Edit
            TextBox mytb = new TextBox();
            mytb = (TextBox)e.Row.FindControl("TextBox8");
            if (mytb != null)
            {
                mytb.Text = DateTime.Now.ToString("yyyy-MM-dd");
            }
        }
    }