iOS 8以上设置APP图标右上角通知数字

前几天运行老版本的代码时，突然报错Attempting to badge the application icon but haven't received permission from the user to badge the application

因为在iOS 8.0之后，设置应用的application badge value需要得到用户的许可，即 用户可以决定是否接收消息通知。。

解决办法：

    if ([[UIDevice currentDevice].systemVersion floatValue] >=8.0){        UIUserNotificationSettings* notificationSettings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound categories:nil];        [[UIApplication sharedApplication] registerUserNotificationSettings:notificationSettings];    }