对[UIApplication sharedApplication] .applicationIconBadgeNumber的更改未立即反映

Question

当用户阅读邮件时，我使用以下代码更改标签栏上的应用程序徽章编号和徽章。我看到一些无法解释的行为。如果在[UIApplication sharedApplication] .applicationIconBadgeNumber = 1时调用该方法，则applicationIconBadgeNumber将递减为0.但除非我在递减和下一个if之间有睡眠（1）（[UIApplication sharedApplication] .applicationIconBadgeNumber＆gt; = 1），如果condition的计算结果为True，则DDLogPrint表示＆＃34;将标签栏标记设置为0，因为appbadge为0＆＃34;。如果我使用睡眠线，那么事情按预期工作（即标签栏徽章设置为零）。

预计对[UIApplication sharedApplication] .applicationIconBadgeNumber的更改可能需要一些时间吗？

-(void) decrementBadges
{

 AppDelegate *appDelegate = (AppDelegate*)[[UIApplication sharedApplication] delegate];
 UITabBarController *myTabBarController = (UITabBarController *)appDelegate.window.rootViewController;
 UITabBarItem *tbItem = (UITabBarItem *)[myTabBarController.tabBar.items objectAtIndex:CHAT_TAB_INDEX];

 DDLogVerbose(@"In decrement badges with badge number = %ld, tab bar icon = %@, numMessageRead=%ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber,tbItem.badgeValue, (long)[[NSUserDefaults standardUserDefaults] integerForKey:@"numMsgRead"]) ;

 if([UIApplication sharedApplication].applicationIconBadgeNumber>=1)
 {
    [UIApplication sharedApplication].applicationIconBadgeNumber-- ;
 }

 //sleep(1) ; //If I uncomment this line, then it works, tab bar badge gets set to nil when method is called with applicationIconBadgeNumber =1
 if([UIApplication sharedApplication].applicationIconBadgeNumber>=1)
 {
    tbItem.badgeValue = [NSString stringWithFormat:@"%ld", (long)[UIApplication sharedApplication].applicationIconBadgeNumber];
    DDLogVerbose(@"Setting tab bar badge to %@ because appbadge is %ld",tbItem.badgeValue,(long)[UIApplication sharedApplication].applicationIconBadgeNumber) ;
 }
 else
 {
    tbItem.badgeValue = nil;
    DDLogVerbose(@"Setting tab bar badge to nil because appbadge is %ld",(long)[UIApplication sharedApplication].applicationIconBadgeNumber) ;
 }
}