iPhone app in the background

Question

Is there any way to start sound or pop-up message from closed iPhone app. Simply like "receive SMS"

Answer 1

Yes, this has actually changed after the question was initially answered.

There are currently at least two ways for a closed application to play a sound or a popup.

1. An app can register for a Local Notification while it is running, that will be called at a future time even if the app is closed. The notification will display a popup and optionaly play a sound or set a badge on an application's icon. Implementing this is easy:

       id localNotif = [[NSClassFromString(@"UILocalNotification") alloc] init];
       if (!localNotif) {
           return;
       }
   
       [localNotif setTimeZone:[NSTimeZone defaultTimeZone]];
       [localNotif setAlertBody:NSLocalizedString(@"Hello!",nil)];
       [localNotif setAlertAction:NSLocalizedString(@"Hello", nil)];
       [localNotif setSoundName:UILocalNotificationDefaultSoundName];
       [localNotif setFireDate:[[NSDate date] addTimeInterval:(60*60)]];           
       [localNotif setFireDate:[[NSDate date] addTimeInterval:(24*60*60)]];
       [[UIApplication sharedApplication] scheduleLocalNotification:localNotif];
       [localNotif release];
   

2. An app (with the user's permission) can register itself with a remote server (yours or a service provider) to receive push notifications delivered to it from you (via Apple's system). Once received, the App will optionally display a popup, play a sound, and/or change the badge on an applications icon. There is sample code in the Apple documentation for implementing the iPhone side of this, and also a few open source projects floating around for the server side. You can bypass having to implement your own server side by using a service like Urban Airship.

Answer 2

I don't believe so. Apple has stated that no third party apps can run in the background (even though some of their apps do this). This is why there was a big deal about "push notifications" last summer (that has since gone no where, unfortunately) - this would allow an app to be sent some data from a server, and then appropriately respond to it.

You might be able to accomplish this if you write an app for a jailbroken iPhone, but then only those users who have jailbroken their phone would be able to install and use your app.

Answer 3

Andy is right but Apple promised to enable their push system for 3th parties as well. So, I think you could just wait till they release it... no idea when though.