iOS 消息提醒数字

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //1. 消息提醒数字
    UIApplication *app = [UIApplication sharedApplication];
    //注册用户的通知.
    UIUserNotificationSettings *userNotice = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];
    [app registerUserNotificationSettings:userNotice];
    
    app.applicationIconBadgeNumber = 15;
    
    
}