private void cbxLoaiDia_SelectedIndexChanged(object sender, EventArgs e) { loadDataTrangThai(); if (cbxLoaiDia.SelectedIndex >= 0) { loaidialay = cbxLoaiDia.SelectedValue.ToString(); lstDiaXem = diaBUS.layDiaTheoLoaiDia(loaidialay); LoadDataToDatagridview(dataGridViewX1, lstDiaXem); } else { lstDiaXem = diaBUS.layToanBoDia(); LoadDataToDatagridview(dataGridViewX1, lstDiaXem); } }