I am currently working on an application built in VS using a Xamarin Unified IOS project. one requirement of the application is the utilisation of push notifications. The issue is that our test device/application registers in the first instance without any issues, we can see the registration events in azure portals, and the azure service bus. I have also confirmed the initial registration using the 'Service Bus Explorer' application and the server explorer feature in VS.
The issue arises when sending the test push notification. According to all the logs I have access too the message is successfully pushed to apples APNS server and I can't see any failures being returned as part of the PNS request. However once this completed the device registration is removed and the notification never arrives on the test device.
My understanding is that the azure application hub handles PNS rejections itself in order to tidy up device registrations. This in and of itself is not a terrible idea, but due to a lack of logging, it's very hard to determine the root cause. I have done a ridiculous amount of googling for this one, and a lot of people suggest an issue with the apple certificates that are used. I have deleted, recreated, resigned, verified, both APNS certs and Provisioning profiles until I ran out of combinations. None of that has resolved the issue.
To make the issue more confusing, if I use a service such as 'http://pushtry.com' or 'http://pushwatch.com' and upload the certificate and device token, it will allow me to successfully push a notification to the device.
Am I missing something glaringly obvious? or is the notification hub absurdly difficult to setup and debug for APNS?
Any help you can provide will be appreciated, I would publish some code, but as I know that the device registers the correct device token, I don't see it necessary at this point, but please feel free to tell me otherwise. Many thanks.
After many man hours and through luck rather than any kind of logical process, we determined that 'Azure Notification Hubs' have an in built validator for the apple device token that's passed up to the APNS. So even though there are multiple examples and answers out there that suggest submitting a device token without spaces or symbols to the notification hub, this is in fact the wrong approach. The device token should always be submitted to the 'Azure Notification Hub' in an 'as is' state, without any validating from within the Xamarin.IOS application. Although this seems like such a simple thing to overlook, there is a lot of contradictory evidence out there on google, and Azure's documentation says very little about the format of submitted device tokens. Anyway hopefully this will help someone else someday.
-- Edit --
Device Token format from Apple: < XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX >
Format that many online resources suggest it is passed to the notification hub as: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX without spaces or the '<' and '>'
However it should be passed through to the notification hub as it is received from Apple.