点击更改不能传值和错误

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;public partial class table_SComputer : System.Web.UI.Page
{
    DBClass obj = new DBClass();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GridViewBind();//绑定自定义方法GridViewBind
            if(Request.QueryString["Oid"]!= null)
            {
                Label2.Text = Request.QueryString["Oid"];
                SqlConnection Conn = obj.GetConnection();
                Conn.Open();
                SqlDataAdapter myda = new SqlDataAdapter("select Oid,Oname,ComputerUse,Price,Display,Keyboard,Mouse,Musicbox,Camera,Need  from OComputer where Oid=" + Request.QueryString["Oid"] + "", Conn);
                DataSet ds = new DataSet();
                myda.Fill(ds, "OComputer");
                DataRowView drv = ds.Tables["OComputer"].DefaultView[0];
                SOname.Text = drv["Oname"].ToString();
                SOComputeruse.Text = drv["ComputerUse"].ToString();
                SOprice.Text = drv["Price"].ToString();
                SOdisplay.Text = drv["Display"].ToString();
                SOkeyboard.Text = drv["Keyboard"].ToString();
                SOmouse.Text = drv["Mouse"].ToString();
                SOmusicbox.Text = drv["Musicbox"].ToString();
                SOCamera.Text = drv["Camera"].ToString();
                SOneed.Text = drv["Need"].ToString();
            }
          
        }
    }
    public void GridViewBind()//绑定GridView控件的自定义方法
    {
        SqlConnection Conn = obj.GetConnection();
        Conn.Open();
        SqlDataAdapter myda = new SqlDataAdapter("select Oid,Oname,ComputerUse,Price,Display,Keyboard,Mouse,Musicbox,Camera,Need from OComputer", Conn);
        DataSet ds = new DataSet();
        myda.Fill(ds, "OComputer");
        GridView1.DataSource = ds;
        GridView1.DataBind();
        Conn.Close();
    }    protected void BTNSOnew_Click(object sender, EventArgs e)
    {
        SqlConnection Conn = obj.GetConnection();
        Conn.Open();
        SqlCommand com = new SqlCommand("update OComputer set Oname='" + SOname.Text + "',ComputerUse='" + SOComputeruse.Text + "',Price='" + SOprice.Text + "',Display='" + SOdisplay.Text + "',Keyboard='" + SOkeyboard.Text + "',Mouse='" + SOmouse.Text + "',Musicbox='" + SOmusicbox.Text + "',Camera='" + SOCamera.Text + "',Need='" + SOneed.Text + "' where Oid=" + Request["Oid"], Conn);
        com.ExecuteNonQuery();
        //Conn.Close();
        GridViewBind();    }
}错误信息:  App_Web_r1iuwpij.dll!table_SComputer.GridViewBind() 行45 C#
> App_Web_r1iuwpij.dll!table_SComputer.Page_Load(object sender = {ASP.table_scomputer_aspx}, System.EventArgs e = {System.EventArgs}) 行20 + 0x7 字节 C#