private void btnAdd_Click(object sender, EventArgs e)
        {
            epName.Clear();
            bool check1 = StaffsHelper.ControlValidate(txtName, "Lütfen Staff İsmini Giriniz.", epName);

            epTCNO.Clear();
            bool check2 = StaffsHelper.ControlValidate(txtTcNo, "Lütfen TC No Giriniz.", epTCNO);

            epAddress.Clear();
            bool check3 = StaffsHelper.ControlValidate(txtAddress, "Lütfen Address İsmini Giriniz.", epAddress);

            epContactNo.Clear();
            bool check4 = StaffsHelper.ControlValidate(txtContactNo, "Lütfen Contact No Giriniz.", epContactNo);

            if (txtTcNo.Text.Trim().Length != 11)
            {
                MessageBox.Show("TC No 11 hanali olmalıdır.", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            if (txtContactNo.Text.Trim().Length < 9 || txtContactNo.Text.Trim().Length > 14)
            {
                MessageBox.Show("Lütfen geçerli bir telefon numarası giriniz!", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            if (check1 && check2 && check3 && check4)
            {
                if (!StaffsHelper.HaveTCNO(txtTcNo.Text.Trim()) && !StaffsHelper.HaveContactNo(txtContactNo.Text))
                {
                    Staffs s = new Staffs();

                    s.DesignationID = DesignationsHelper.GetByName(cmbDesignation.SelectedItem.ToString());
                    s.Name          = txtName.Text;
                    s.TCNO          = txtTcNo.Text;
                    s.Gender        = cmbGender.SelectedIndex;
                    s.Address       = txtAddress.Text;
                    s.ContactNo     = txtContactNo.Text;
                    s.Status        = 1;

                    StaffsHelper.Add(s);

                    MessageBox.Show("Staff Ekleme Başarılı", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    FillGrid();
                }
                else
                {
                    MessageBox.Show("Girdiğiniz TC veya Telefon numarası sistemde kayıtlıdır.", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }
        private void btnUpdate_Click(object sender, EventArgs e)
        {
            epName.Clear();
            bool check1 = StaffsHelper.ControlValidate(txtName, "Lütfen Staff İsmini Giriniz.", epName);

            epTCNO.Clear();
            bool check2 = StaffsHelper.ControlValidate(txtTcNo, "Lütfen TC No Giriniz.", epTCNO);

            epAddress.Clear();
            bool check3 = StaffsHelper.ControlValidate(txtAddress, "Lütfen Address İsmini Giriniz.", epAddress);

            epContactNo.Clear();
            bool check4 = StaffsHelper.ControlValidate(txtContactNo, "Lütfen Contact No Giriniz.", epContactNo);

            if (check1 && check2 && check3 && check4)
            {
                int selectIndex = dgvStaffList.CurrentRow.Index;
                var staffID     = dgvStaffList.Rows[selectIndex].Cells[0].Value;

                var s = StaffsHelper.GetById(Convert.ToInt32(staffID));

                s.DesignationID = DesignationsHelper.GetByName(cmbDesignation.SelectedItem.ToString());
                s.Name          = txtName.Text;
                s.TCNO          = txtTcNo.Text;
                s.Gender        = cmbGender.SelectedIndex;
                s.Address       = txtAddress.Text;
                s.ContactNo     = txtContactNo.Text;

                StaffsHelper.Update(s);

                MessageBox.Show("Staff güncelleme başarılı", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Information);
                ClearForm();
                FillGrid();
                DisableComponent();
            }
        }