iOS8-在有效负载中添加“ sound”属性之前，无声推送通知不起作用

Question

I have an application with Push notifications enabled.I add background modes, add logic for registration for both iOS versions and they should work equally. In iOS7 this works as expected (Application "wake up" and fetch data):

"customJson":{ },
"aps":{"content-available":1}

In iOS8 to do the same thing I have to add empty sound,otherwise didReceiveRemoteNotification: fetchCompletionHandler: method is not executed:

"customJson":{ },
"aps":{"content-available":1,sound:""}

For registration I use workaround from this question. Why this happen,any ideas?

Answer 1

Had the same problem before, seems like this is a bug with silent push notifications. I added

sound:""

like you did and it worked.

What I've learned is, that silent notifications will not be handled by the system when the user fore-quit'ed the app (killed via swipe on task manager): https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/index.html#//apple_ref/occ/intfm/UIApplicationDelegate/application:didReceiveRemoteNotification:fetchCompletionHandler : So if the user killed the app, it shouldn't do anything in the background anymore. This makes sense from a user's perspective.

Answer 2

Have you tried adding remote-notification to Info.plist UIBackgroundModes array? You need to have that entry for silent notifications to work.