GridView1_RowUpdating更新不了，求助
代码如下：
   protected void GridView1_RowUpdating1(object sender, GridViewUpdateEventArgs e)
    {
        string strConn = System.Configuration.ConfigurationManager.AppSettings["DSN"];
        SqlConnection conn = new SqlConnection(strConn);
        conn.Open();

        string s1 = GridView1.DataKeys[e.RowIndex].Value.ToString();
        string s2 = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[1].Controls[0])).Text;
        string s3 = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[2].Controls[0])).Text;
        string s4 = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[3].Controls[0])).Text;
        string s5 = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[4].Controls[0])).Text;
        string sql = "update 户型资料表 set 户型='" + s2 + "',房型='" + s3 + "',套内面积='" + s4 + "',简介='" + s5 + "' where 户型编号='" + s1 + "'";
        SqlCommand cmd = new SqlCommand(sql, conn);
        
        cmd.ExecuteNonQuery();
        conn.Close(); 
    }




数据库表如下：
<asp:GridView ID="GridView1"  runat="server" Height="217px" Width="651px" AllowPaging="True" BackColor="White" BorderColor="#DEDFDE" BorderStyle="None" BorderWidth="1px" CellPadding="4" EnableSortingAndPagingCallbacks="True" PageSize="5" AllowSorting="True" AutoGenerateColumns="False" ForeColor="Black" GridLines="Vertical" OnRowCancelingEdit="GridView1_RowCancelingEdit" OnRowDeleting="GridView1_RowDeleting" OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating1" DataKeyNames="户型编号" >
        <FooterStyle BackColor="#CCCC99" />
        <RowStyle BackColor="#F7F7DE" />
        <SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />
        <PagerStyle ForeColor="Black" HorizontalAlign="Right" BackColor="#F7F7DE" />
        <HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" />
        <Columns>
            <asp:BoundField DataField="户型编号" HeaderText="户型编号" SortExpression="户型编号" />
            <asp:BoundField DataField="户型" HeaderText="户型" SortExpression="户型" />
            <asp:BoundField DataField="房型" HeaderText="房型" SortExpression="房型" />
            <asp:BoundField DataF