How to remove single notification in Notification Center?

How do you ensure that your app's notifications are cleared from Notification Center after a user views the related item?

• For example, when displays a notification for a new picture posted by a friend and I go to view the picture, the notification isn't cleared from Notification Center. There is actually no way to clear these notifications other than to tap "x" and then "clear" in Notification Center. Tapping on the notification, viewing the related items in app and/or simply opening the app do not clear the notifications. What code/triggers does Path need to include to ensure that the notification will be cleared from Notification Center? There is definitely something that can be done to clear the notifications after viewing because 's notifications disappear after viewing the item, while and 's notifications are never cleared until you tap the "x" and then "clear" to explicitly clear them. Why/how do some apps clear these notifications after viewing while others don't?

• Answer:

  There's no explicit "consume notification" call that relates to the notification center, nor any specific documentation I can find regarding what causes notifications to disappear from the notification center. However, as you note, it's obviously possible, and is handled differently depending on the app. From what I can gather, this is an all or nothing thing-- as in, you can clear out the notification center for your app but not selectively clear individual notifications. The key steps seem to be: Set the app's icon badge number to 0. (You can later reset it to its previous value if it makes sense-- the important thing seems to be to make it zero, even temporarily). call cancelAllLocalNotifications (even if you're only using push notifications). Make sure these steps happen both when the app finishes launching and when it becomes the foreground app. This is somewhat guesswork since I haven't tried it and don't have time to put together a test project to verify it. If I wanted to clear notification center messages for an app though, this is where I'd start. I wonder if would be willing to comment on what the Quora app does here, since it's in the camp of clearing messages from the notification center.