ios7与ios8并存,注册推送通知

 // IOS8 新系统需要使用新的代码咯    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)    {        [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings                                                                             settingsForTypes:(UIUserNotificationTypeSound |UIUserNotificationTypeAlert | UIUserNotificationTypeBadge)                                                                             categories:nil]];                        [[UIApplication sharedApplication] registerForRemoteNotifications];    }    else    {        //ios7注册推送通知        [[UIApplication sharedApplication] registerForRemoteNotificationTypes:         (UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert)];    }