private void btnAdd_Click(object sender, EventArgs e)
        {
            Lecture lecture = new Lecture();

            lecture.L_ID         = this.txtLectureID.Text.Trim();
            lecture.L_name       = this.txtLecturename.Text.Trim();
            lecture.L_fullname   = this.txtFullname.Text.Trim();
            lecture.L_department = this.cmbDepartment.Text.Trim();
            lecture.L_gender     = this.cmbGender.Text.Trim();
            lecture.L_birthday   = DateTime.Parse(this.dateTimeBirthday.Text.Trim());
            lecture.L_email      = this.txtEmail.Text.Trim();
            lecture.L_phone      = this.txtPhone.Text.Trim();



            if (LectureController.addLecture(lecture) == false)
            {
                MessageBox.Show("Error in adding a new lecture!!!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }


            BindingSource source = new BindingSource();

            source.DataSource          = LectureController.getAllLecture();
            this.dgvLecture.DataSource = source;
        }
        private void btnUpdate_Click(object sender, EventArgs e)
        {
            Lecture lecture = new Lecture();

            lecture.L_ID = this.dgvLecture.CurrentRow.Cells[0].Value.ToString();
            if (lecture.L_ID.Length <= 0)
            {
                return;
            }

            if (this.dgvLecture.CurrentRow.Cells[1].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[1].Value = "";
            }
            lecture.L_name = this.txtLecturename.Text.Trim();

            if (this.dgvLecture.CurrentRow.Cells[2].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[2].Value = "";
            }
            lecture.L_fullname = this.txtFullname.Text.Trim();
            if (this.dgvLecture.CurrentRow.Cells[3].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[3].Value = "";
            }
            lecture.L_department = this.cmbDepartment.Text.Trim();
            if (this.dgvLecture.CurrentRow.Cells[4].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[4].Value = "";
            }
            lecture.L_gender = this.cmbGender.Text.Trim();
            if (this.dgvLecture.CurrentRow.Cells[5].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[5].Value = "";
            }
            lecture.L_birthday = this.dateTimeBirthday.Value;
            if (this.dgvLecture.CurrentRow.Cells[6].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[6].Value = "";
            }
            lecture.L_phone = this.txtPhone.Text.Trim();
            if (this.dgvLecture.CurrentRow.Cells[7].Value is null)
            {
                this.dgvLecture.CurrentRow.Cells[7].Value = "";
            }
            lecture.L_email = this.txtEmail.Text.Trim();
            if (LectureController.UpdateLecture(lecture) == false)
            {
                MessageBox.Show("Cannot update!!!");
            }
            else
            {
                MessageBox.Show("Update success", "Note", MessageBoxButtons.OK);
                BindingSource source = new BindingSource();
                source.DataSource          = LectureController.getAllLecture();
                this.dgvLecture.DataSource = source;
            }
        }
        public frmLecture()
        {
            InitializeComponent();

            this.cID.DataPropertyName          = nameof(Lecture.L_ID);
            this.cLecturename.DataPropertyName = nameof(Lecture.L_name);
            this.cFullname.DataPropertyName    = nameof(Lecture.L_fullname);
            this.cDepartment.DataPropertyName  = nameof(Lecture.L_department);
            this.cGender.DataPropertyName      = nameof(Lecture.L_gender);
            this.cBirthday.DataPropertyName    = nameof(Lecture.L_birthday);
            this.cPhone.DataPropertyName       = nameof(Lecture.L_phone);
            this.cEmail.DataPropertyName       = nameof(Lecture.L_email);
            this.cmbGender.DataSource          = listgender;
            this.cmbDepartment.DataSource      = listdepartment;
            BindingSource source = new BindingSource();

            source.DataSource          = LectureController.getAllLecture();
            this.dgvLecture.DataSource = source;
        }
        private void btnDelete_Click(object sender, EventArgs e)
        {
            if (this.dgvLecture.SelectedRows.Count <= 0)
            {
                return;
            }
            string idlecture = this.dgvLecture.SelectedRows[0].Cells[0].Value.ToString().Trim();

            if (LectureController.DeleteLecture(idlecture) == false)
            {
                MessageBox.Show("Cannot delete lecture!!!");
            }
            else
            {
                MessageBox.Show("Delete success!!!", "Note", MessageBoxButtons.OK);
                BindingSource source = new BindingSource();
                source.DataSource          = LectureController.getAllLecture();
                this.dgvLecture.DataSource = source;
            }
        }