private void btnTimKiem_Click(object sender, EventArgs e)
        {
            gridLop.DataSource = BangDiemLogic.SelectDSLop(GlobalSettings.UserID, rdKhoangThoiGian.Checked ? (DateTime?)DateTime.ParseExact(dateTuNgay.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture) : null,
                                                           rdKhoangThoiGian.Checked ? (DateTime?)DateTime.ParseExact(dateDenNgay.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture) : null, rdKhoaHoc.Checked ? O2S_Common.TypeConvert.Parse.ToInt32(cboKhoaHoc.SelectedValue.ToString()) : 0);

            gridLop_Click(sender, e);
        }
        private void frmBangDiem_Load(object sender, EventArgs e)
        {
            lblTitle.Text = string.Format("Bảng điểm của {0}", TaiKhoanLogic.FullUserName(new TAIKHOAN()
            {
                TenDangNhap = GlobalSettings.UserCode
            }));
            cboLop.DataSource    = BangDiemLogic.SelectDSLop(GlobalSettings.UserID);
            cboLop.DisplayMember = "TenLopHoc";
            cboLop.ValueMember   = "LopHocId";

            lblTenLop.Text = lblTenKhoaHocoa.Text = string.Empty;

            lblDiemTrungBinh.Text = 0.ToString();

            isLoaded = true;
            cboLop_SelectedValueChanged(sender, e);
        }
        private void btnXemTatCa_Click(object sender, EventArgs e)
        {
            gridLop.DataSource = BangDiemLogic.SelectDSLop(GlobalSettings.UserID, null, null, 0);

            gridLop_Click(sender, e);
        }