/** 查询选中省内所有的市，优先从数据库查询，如果没有查询到再去服务器上查询。 */
private void queryCities() {
cityList = coolWeatherDB.loadCities(selectedProvince.getId());
if (cityList.size() > 0) {
dataList.clear();
for (City city : cityList) {
dataList.add(city.getCityName());
}
adapter.notifyDataSetChanged();
listView.setSelection(0);
titleText.setText(selectedProvince.getProvinceName());
currentLevel = LEVEL_CITY;
} else {
queryFromServer(selectedProvince.getProvinceCode(), "city");
}
}
