After uploading a file its not appearing in gridview

protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e)
        {
           SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=MinisanteDb;Integrated Security=True");
            SqlCommand com = new SqlCommand("select name,type,data from  uploadd where name=@name", con);
            com.Parameters.AddWithValue("name", GridView1.SelectedRow.Cells[1].Text);
            con.Open();
            //con.Close();

            SqlDataReader dr = com.ExecuteReader();


            if (dr.Read())
            {
                Response.Clear();
                Response.Buffer = true;
                Response.ContentType = dr["type"].ToString();
                Response.AddHeader("content-disposition", "attachment;filename=" + dr["name"].ToString());     // to open file prompt Box open or Save file         
                Response.Charset = "";
                Response.Cache.SetCacheability(HttpCacheability.NoCache);
                Response.BinaryWrite((byte[])dr["data"]);
                Response.End();
            }
        }