private void grvDSLop_FocusedRowChanged(object sender, DevExpress.XtraGrid.Views.Base.FocusedRowChangedEventArgs e) { if (e.FocusedRowHandle >= 0) { dtData = oBSV_SinhVien.GetByLop_Mon(int.Parse(grvDSLop.GetDataRow(e.FocusedRowHandle)["DM_LopID"].ToString()), IDDM_MonHoc, Program.IDNamHoc, Program.HocKy, IDKQHT_HoiDongMon); if (dtData != null && dtData.Rows.Count == 0) { dtData = oBKQHT_HoiDongMon_SinhVien.GetByThiTotNghiep(int.Parse(grvDSLop.GetDataRow(e.FocusedRowHandle)["DM_LopID"].ToString()), IDDM_MonHoc, Program.IDNamHoc, Program.HocKy, IDKQHT_HoiDongMon); } grdSinhVien.DataSource = dtData; dtData.AcceptChanges(); if (dtData.Rows.Count > 0) { btnThem.Enabled = true; } else { btnThem.Enabled = false; } } }