private void pictureBox5_Click(object sender, EventArgs e)
        {
            Close();
            var a = new FrmKullaniciMenu(info);

            a.Visible = true;
        }
        private void girisBT_Click(object sender, EventArgs e)
        {
            using (OracleCommand cmd = con.CreateCommand())
            {
                try
                {
                    con.Open();
                    cmd.CommandText = "SELECT OgrTC,OgrId,OgrAd,OgrOdaId FROM yogrenci WHERE OgrTC=:OgrTC AND OgrPass=:OgrPass";
                    cmd.Parameters.Add(new OracleParameter("OGRTC", maskedTextBox1.Text));
                    cmd.Parameters.Add(new OracleParameter("OGRPASS", GirisSifreTB.Text));
                    OracleDataReader reader2 = cmd.ExecuteReader();

                    if (reader2.Read())
                    {
                        OgrBilgi info = new OgrBilgi();
                        info.ID    = reader2.GetInt64(1);
                        info.Isim  = reader2.GetString(2);
                        info.TC    = reader2.GetString(0);
                        info.OdaID = reader2.GetInt64(3);
                        var c = new FrmKullaniciMenu(info);
                        c.Visible = true;
                        Close();
                    }
                    else
                    {
                        MessageBox.Show("Hatalı şifre veya TC numarası girdiniz!");
                        maskedTextBox1.Clear();
                        GirisSifreTB.Clear();
                        maskedTextBox1.Focus();
                    }  reader2.Dispose();
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
                con.Close();
            }
        }