// 点击城市发出通知- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {    // 1. 发送点击的城市名    DJCityGroup *cityGroup = self.cityGroups[indexPath.section];    [[NSNotificationCenter defaultCenter] postNotificationName:DJCityDidChangeNotification object:nil userInfo:@{DJSelectCityName:cityGroup.cities[indexPath.row]}];    // 2. 关闭当前controller    [self dismissViewControllerAnimated:YES completion:nil];    }

/** 监听到城市改变广播 */- (void)onReceiveCityChangeNotification:(NSNotification *)notification {    NSString *selectedCityName = notification.userInfo[DJSelectCityName];        // 1. 更新当前显示地区    DJNavItem *areaView = self.areaItem.customView;    [areaView setTitle:[NSString stringWithFormat:@"%@ - 全部",selectedCityName]];    }

#import <Foundation/Foundation.h>/* 通知 */NSString *const DJCityDidChangeNotification = @"DJCityDidChangeNotification";NSString *const DJSelectCityName = @"DJSelectCityName";