iOS UILocalNotification用于传入SIP通知

Question

After getting sip notification how to show it to user using UILocalNotification when app is in background.

App's Background mode is ->voip and it is always alive in background .

just it can not show notification after getting sip call when it is in background.

Answer 1

It's a little difficult to tell what your question is, but I can tell you that a UILocalNotification will present itself to the user exactly as is described in Apple's documentation at "Local and Push Notification Programming Guide" > "Handling Local and Remote Notifications". Specifically:

1. If your app is in the background or has been terminated, iOS will display the local notification for you using the properties defined when the UILocalNotification was created & configured.
2. If your app is in the foreground, iOS won't automatically display your notification -- you must implement UIApplicationDelegate's -application:didReceiveLocalNotification: and present (or not present) the notification as you see fit.

And don't forget forget to actually schedule your UILocalNotification with -[UIApplication sharedApplication] using the -scheduleLocalNotification: method. Just creating the UILocalNotification won't do anything.

AND, I think you need to use UIApplication's -registerForRemoteNotificationTypes: even for local notifications.

Just as an aside unrelated to Local Notifications, because we struggled with VOIP backgrounding as well, note that just because you set the Background mode to VOIP, doesn't mean your app will always be running. Any of the following will lead to iOS terminating your app:

• You use UDP for your VOIP socket. iOS doesn't appear to support backgrounding with UDP, only TCP.
• If your VOIP socket connection receives more than 30 "wakes" within 300 seconds.
• If your VOIP socket is disconnected, you must request background execution time while you attempt to reconnect. But if you are unable to reconnect after the amount of backgrounding time iOS gives you, the app will be terminated.

So you should confirm (through tracing or something else) that your VOIP signaling channel is, in fact, alive in the background when you're testing local notifications.

In conclusion, you have a lot of investigating & troubleshooting to do :)