private void BtnPhongTro_Click(object sender, EventArgs e) { try { ExportToExcel excel = new ExportToExcel(); PhongTroBAL bal = new PhongTroBAL(); DataTable dt = bal.DTDS(); excel.ExportPT(dt, "Phòng trọ", "Danh sách phòng trọ"); } catch (Exception ex) { MessageBox.Show(ex.Message); } }