当新的推送通知到达时，我如何更新uitabbaritem的徽章号码?

Question

当新的推送通知到达时，我如何更新特定UITabBarItem的徽章?例如Instagram中的activity选项卡

Answer 1

应该使用以下代码:

[[[[[self tabBarController] tabBar] items] 
               objectAtIndex:tabIndex] setBadgeValue:badgeValueString];

Answer 2

NSString *badgeValue = [NSString stringWithFormat:@"%lu", (long)countUnreadMessages];
[[[[self viewControllers] objectAtIndex:indexOfTabbarItem] tabBarItem] setBadgeValue:([badgeValue isEqualToString:@"0"]) ? nil : badgeValue];