public void LoadDanhSachSV()
{
gcDanhSach.DataSource = null;
gcDanhSach.Controls.Clear();
var dao = new SinhVienDAO();
var lst = new List <SinhVien>();
var ids = string.Join(",", cbbDanhSachLop.Properties.Items.GetCheckedValues());
var ser = txtSearch.Text;
if (string.IsNullOrEmpty(ids))
{
lst = dao.GetAll(ser);
}
else
{
lst = dao.GetAllByLop(ids, ser);
}
gcDanhSach.DataSource = lst;
}