private void btnThem_Click(object sender, EventArgs e)
{
txtIDHocSinh.Text = (HocSinhDAO.IDMax() + 1).ToString();
lc = LuaChon.Them;
AnButton();
UnReadOnly();
txtHoTen.Text = "";
txtSDT.Text = "";
txtDiaChi.Text = "";
}
private void ThemHocSinh()
{
HocSinhDTO hs = new HocSinhDTO();
hs.HoTen = txtHoTen.Text;
hs.GioiTinh = rdbNam.Checked ? "Nam" : "Nữ";
hs.SDT = txtSDT.Text;
hs.NgaySinh = dtpNgaySinh.Value.ToShortDateString();
hs.IDLop = (int)cboLop.SelectedValue;
hs.DiaChi = txtDiaChi.Text;
hs.IDHocSinh = HocSinhDAO.IDMax() + 1;
HocSinhDAO.ThemHS(hs);
}