ASP.Net GridView RowUpdating Error: Object reference not set to an instance of an object

Hello everyone, i have done everything fine but still cant update my gridview data when i click on edit button Why ?

error showing is that - Object reference not set to an instance of an object on this line

string id1 =((Label)GridView1.Rows[e.RowIndex].FindControl("Label1")).Text;

Here are my HTML

    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="id"
        BackColor="#DEBA84" BorderColor="#DEBA84" BorderStyle="None" BorderWidth="1px"
        CellPadding="3" CellSpacing="2" Height="344px" Width="911px"
        onrowcancelingedit="GridView1_RowCancelingEdit"
        onrowediting="GridView1_RowEditing" onrowupdating="GridView1_RowUpdating">
        <RowStyle BackColor="#FFF7E7" ForeColor="#8C4510" />
        <Columns>
            <asp:TemplateField HeaderText="ID">
                <ItemTemplate>
                    <asp:Label ID="Label1" runat="server" Text='<%# Eval("id") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="NAME">
                 
                <ItemTemplate>
                    <asp:Label ID="Label2" runat="server" Text='<%# Eval("name") %>'></asp:Label>
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:TextBox ID="txtedititemname" runat="server" Text='<%# Eval("name") %>'></asp:TextBox>
                </EditItemTemplate>
            </asp:TemplateField>
            
            <asp:CommandField ShowEditButton="True" />
        </Columns>
        <FooterStyle BackColor="#F7DFB5" ForeColor="#8C4510" />
        <PagerStyle ForeColor="#8C4510" HorizontalAlign="Center" />
        <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#A55129" Font-Bold="True" ForeColor="White" />
    </asp:GridView>

C# code

    string str = null;
 
    protected void Page_Load(object sender, EventArgs e)
    {
        bindgrid();
        if (!IsPostBack)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["conn"].ToString());
            con.Open();
 
            SqlCommand cmd = new SqlCommand("select catid,catname from Category_Update", con);
            DropDownList1.DataTextField = "catname";
            DropDownList1.DataSource = cmd.ExecuteReader();
            DropDownList1.DataValueField = "catid";
            DropDownList1.DataBind();
        }
    }
 
    protected void btnsubmit_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            str = "~/Product_Images_Update/" + FileUpload1.FileName;
            FileUpload1.SaveAs(MapPath(str));
 
            SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["conn"].ConnectionString);
            con.Open();
 
            SqlCommand cmd = new SqlCommand("insert into Admin_Product_Update(id,name,description,price,image)values(@proid,@proname,@prodescrp,@proprice,@str)", con);
            cmd.Parameters.AddWithValue("@proid", txtpid.Text);
            cmd.Parameters.AddWithValue("@proname", txtpname.Text);
            cmd.Parameters.AddWithValue("@prodescrp", txtpdescript.Text);
            cmd.Parameters.AddWithValue("@proprice", txtpprice.Text);
            cmd.Parameters.AddWithValue("@str", str);
 
            int a = cmd.ExecuteNonQuery();
 
            if (a > 0)
            {
                lblmsg.Text = "succesful";
                txtpname.Text = "";
                txtpdescript.Text = "";
                txtpprice.Text = "";
                txtpid.Text = "";
 
            }
            else
            {
                lblmsg.Text = "Error";
            }
            bindgrid();
        }
        else
        {
            lblmsg.Text = "please select image";
        }
    }
 
    void bindgrid()
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["conn"].ConnectionString);
        con.Open();
 
        SqlCommand cmd = new SqlCommand("select * from Admin_Product_Update", con);
        SqlDataAdapter sda = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        sda.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
        
    }
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
        GridView1.EditIndex = e.NewEditIndex;
        bindgrid();
    }
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        GridView1.EditIndex = -1;
        bindgrid();
    }
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        var index = e.RowIndex;
        GridView row = GridView1.Rows[index];
        string id1 = ((Label)GridView1.Rows[e.RowIndex].FindControl("Label1")).Text;
        string id = GridView1.DataKeys[row.RowIndex].Values[0].ToString();
        string name = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("txtedititemname")).Text;
 
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["conn"].ToString());
        con.Open();
 
        string update = "update Admin_Product_Update set name='" + name + "' where id='"+id+"'";
        SqlCommand cmd = new SqlCommand(update, con);
        DataTable dt = new DataTable();
        cmd.ExecuteNonQuery();
        GridView1.DataSource = dt;
        GridView1.EditIndex = -1;
        bindgrid();
        con.Close();
    }