void insereazaInTree(Activitate a)
 {
     if (a.getZiua() == "Luni")
     {
         treeViewActivitati.Nodes[0].Nodes.Add(a.ToString());
     }
     else if (a.getZiua() == "Marti")
     {
         treeViewActivitati.Nodes[1].Nodes.Add(a.ToString());
     }
     else if (a.getZiua() == "Miercuri")
     {
         treeViewActivitati.Nodes[2].Nodes.Add(a.ToString());
     }
     else if (a.getZiua() == "Joi")
     {
         treeViewActivitati.Nodes[3].Nodes.Add(a.ToString());
     }
     else if (a.getZiua() == "Vineri")
     {
         treeViewActivitati.Nodes[4].Nodes.Add(a.ToString());
     }
 }
        private void button1_Click(object sender, EventArgs e)
        {
            Adauga add = new Adauga();

            add.ShowDialog();

            Activitate a = add.GetActivitate();

            activitati.Add(a);

            if (add.getStatus())
            {
                using (DbConnection connection = factory.CreateConnection())
                {
                    connection.ConnectionString = ConnString;
                    connection.Open();

                    DbCommand command = connection.CreateCommand();
                    command.CommandText = "SELECT MAX(Nr_activitate) FROM Activitati";
                    int nrAct = (int)command.ExecuteScalar();

                    command.CommandText = "INSERT INTO Activitati VALUES(@p1,@p2,@p3,@p4,@p5,@p6,@p7,@p8)";

                    command.Parameters.Clear();
                    DbParameter p1 = command.CreateParameter();
                    p1.DbType = DbType.Int32;
                    p1.Value  = nrAct + 1;
                    command.Parameters.Add(p1);

                    DbParameter p2 = command.CreateParameter();
                    p2.DbType = DbType.String;
                    p2.Value  = a.getTip();
                    command.Parameters.Add(p2);

                    DbParameter p3 = command.CreateParameter();
                    p3.DbType = DbType.String;
                    p3.Value  = a.getMaterie();
                    command.Parameters.Add(p3);

                    DbParameter p4 = command.CreateParameter();
                    p4.DbType = DbType.String;
                    p4.Value  = a.getOra();
                    command.Parameters.Add(p4);

                    DbParameter p5 = command.CreateParameter();
                    p5.DbType = DbType.String;
                    p5.Value  = a.getGrupa();
                    command.Parameters.Add(p5);

                    DbParameter p6 = command.CreateParameter();
                    p6.DbType = DbType.String;
                    p6.Value  = a.getZiua();
                    command.Parameters.Add(p6);

                    DbParameter p7 = command.CreateParameter();
                    p7.DbType = DbType.String;
                    p7.Value  = a.getSala();
                    command.Parameters.Add(p7);

                    DbParameter p8 = command.CreateParameter();
                    p8.DbType = DbType.Int32;
                    p8.Value  = add.getIdProfesor();
                    command.Parameters.Add(p8);

                    command.ExecuteNonQuery();

                    MessageBox.Show("S-a adaugat: " + a.ToString());
                }
            }
        }