如果应用程序在 iOS 9 上处于后台，则不会出现推送通知

Question

I'm having an issue with push notifications and it affects only my devices running iOS 9:

1. I have my app installed in a set of devices. I run it and register for push notifications with the following code:

if ([application respondsToSelector:@selector(registerUserNotificationSettings:)]) {
    UIUserNotificationType userNotificationTypes = (UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound);
    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:userNotificationTypes categories:nil];
    [application registerUserNotificationSettings:settings];
    [application registerForRemoteNotifications];
}

2. The app is put on background on all devices.
3. I send push notifications to all devices - and get the response that it succeeded.
4. All iOS 8 devices display the push notification in the notification center.
5. NO iOS 9 device display the push notification in the notification center.
6. Open the app in any of the iOS 9 devices in some random moment. The notification is displayed (triggered by application:didReceiveRemoteNotification: ).

Has anything changed on iOS 9? How can I make the push notifications display also on iOS 9, even if the app is not active? I don't want to use notifications to fetch any content in background, I just need to display a message.

Answer 1

In the end, I had to do two things that made it work for me:

• Enable " Remote Notifications " for Background Modes under the Application capabilities (in the target settings)
• Send the notifications with high priority (when they were sent with low priority, they were not being handled with the application on background)

Answer 2

It seems you are OK. This is my code, i get notification in iOS 9.0 also.

-(void)registarPushNotification:(UIApplication*)application
{
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
    {    
        UIUserNotificationType types = UIUserNotificationTypeBadge |  UIUserNotificationTypeSound | UIUserNotificationTypeAlert;

        UIUserNotificationSettings *mySettings = [UIUserNotificationSettings settingsForTypes:types categories:nil];

        [application registerUserNotificationSettings:mySettings];
        [application registerForRemoteNotifications]; 
    }
    else
    {
        [application registerForRemoteNotificationTypes:(UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert)];
    }
}

Answer 3

I think that the user has to tap the notification to bring the app to the foreground and then application(_:didReceiveRemoteNotification:) will be called.

See here: https://www.raywenderlich.com/123862/push-notifications-tutorial