c#picturebox读取sqlserver

         SqlConnection conn = new SqlConnection("server=127.0.0.1,8827;" + "uid=sa;pwd=sa;" + "database=ltbanks");//获得conn连接  
        try
        {
            conn.Open();
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = "SELECT bkxx_tp FROM bkxx WHERE bkxx_xh='" + textBox3.Text + "'";//查询获得图片流  

            SqlDataReader reader = cmd.ExecuteReader();//创建一个OracleDateReader对象   
            reader.Read();

            MemoryStream ms = new MemoryStream((byte[])reader["bkxx_tp"]);

            Image image = Image.FromStream(ms, true);

            reader.Close();
            conn.Close();

            pictureBox1.Image = image;
        }
        catch (Exception ee)
        {
            MessageBox.Show(ee.Message.ToString());
        } 


读取sqlserver中的bkxx_tp字段image类型的blob图片，哪里出问题了？

异常信息是什么？？？

确认reader中是否读到数据