iOS push新的调用方法

// IOS8 新系统需要使用新的代码
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
{
    [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings 
     settingsForTypes:(UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge)      
categories:nil]];

[[UIApplication sharedApplication] registerForRemoteNotifications];
}
else
{
//这里还是原来的代码
    [[UIApplication sharedApplication] registerForRemoteNotificationTypes:
     (UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert)];
}