(Solved) unable to cast object of type 'system.byte ' to type 'system.string' (combobox populate PictureBox)

Question

and sorry for the inconvenience. I hope you can help me, I have this code. which by selecting a combobox populates a series of textboxes, Now I would like to make sure to add, in addition to the textbox, also a picturebox. but I get the error as per the title? How can I proceed. Here is the code. Thanks everyone for the help.

// STRINGA CHE PERMETTE DALLA COMBOBOX VIA DI DETERMINARE IL REFERENTE
    private void cboVia_SelectedIndexChanged(object sender, EventArgs e)
    {
        string str = constring;
        SqlConnection con2 = new SqlConnection(str);
        string query = "SELECT Referenti.IDReferenti, Referenti.CognomeRF, Referenti.NomeRF, Referenti.ZonaRF, Referenti.LinkRF, Referenti.CodiceFotoRF, Referenti.TelefonoRF, Referenti.EmailRF, Referenti.ImageRF, Vie.Settore, Vie.Zona, Vie.Via FROM  Referenti FULL OUTER JOIN  Vie ON Referenti.ZonaRF = Vie.Zona where Via = '" + cboVia.Text + "'";
        SqlCommand cmd = new SqlCommand(query, con2);
        SqlDataReader dbr;
        try
        {

            con2.Open();

            dbr = cmd.ExecuteReader();
            while (dbr.Read())
            {
                //string sID = (string)dbr["IDReferenti"].ToString();
                string CognomeReferente = (string)dbr["CognomeRF"]; // name is string value
                string NomeReferente = (string)dbr["NomeRF"];
                string ZonaReferente = (string)dbr["ZonaRF"];
                string EmailReferente = (string)dbr["EmailRF"];
                string CodiceFotoReferente = (string)dbr["CodiceFotoRF"];
                string imageRF = (string)dbr["ImageRF"];
                //txtID.Text = sID;
                txtCognomeReferente.Text = CognomeReferente;
                txtnomeReferente.Text = NomeReferente;
                txtEmailReferente.Text = EmailReferente;
                txtZona.Text = ZonaReferente;
                txtcodiceFotoReferente.Text = CodiceFotoReferente;
                // PICTUREBOX
                imageRFPictureBox.ImageLocation = imageRF;
                //PICTUREBOX
            }
        }
        catch (System.Exception ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Errore");
        }
    }
    // FINE STRINGA CHE PERMETTE ALLA COMBOBOX VIA DI DETERMINARE IL REFERENTE

Answer 1

@SeanSkelly thanks! Thanks to your advice maybe I found the solution!

byte[] imageRF = (byte[])dbr["ImageRF"];
if (imageRF == null)
                {
                    imageRFPictureBox.Image = null;
                }
                else
                {
                    MemoryStream mstream = new MemoryStream(imageRF);

                    imageRFPictureBox.Image = System.Drawing.Image.FromStream(mstream);
                }

            }
        }
        catch (System.Exception ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Errore");
        }