I created a music app that is wired up to MPNowPlayingInfoCenter. I have a bunch of methods that do various things (next, pause, etc). However, when I hit the next button in MPNowPlayingInfoCenter, the app responds immediately and calls the method instantly when the app is active. However, when the app is playing the background and I hit next from MPNowPlayingInfoCenter, it responds but after a few seconds.
Has anyone else experienced this or have any idea what the culprit might be here?
You shouldn't use any graphics code from the background - iOS will kill your app if you do so too much as it takes away from the resources available to foreground apps. It'll also cripple your other background routines.
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I'm currently working on an app which reminds the user, when he gets to an certain location. I want this app working in background as well and searched for solutions.
In the AppStore i found the App called Sleep Cycle, which tracks your activities during your sleep. When you set the alarm, and running the App in the Background you get this screen red bar on the top of the Display of your iPhone.
http://i.stack.imgur.com/uEejp.jpg
Does anybody know what kind of Backgroundmode this is, and how i can transfer it to my app?
Thanks
To have such a red bar I use audio background mode and also I record sound in background. Since Sleep Cycle asks user to allow access to microphone I believe it also records audio in background
I have a music signal processor app I want to publish and it needs to run in the back ground. I used to Info-plist to do so with UIBackgroundModes. It runs on IOS7 or less, and the problem I am having is once the phone locks and the app goes into the background I can't get it to come out of the background and its keeps running with the red banner at the top. Some of this I have learned as I go, but I have noticed some run on a timer, but I want mine, since its a music processor to keep going until the phone either unlocks or whatever interrupted it stops.
The app is basically a stomp box used with iRig. If that helps.
Thanks
Can you clarify about what you mean when the phone locks, the app goes into the background and yo can't get it to come out of the background? Are you saying like the app is playing music while the app is locked?
We've been using the AIR sound API, building for iOS, with no problems till now, the problem is that the sound works until iPad goes to sleep and there's no sound from our app when iPad is woken back up.
Note: we have the app set to exit on suspend, and we don't have this problem when user suspends -- i.e, hits the button and goes back to desktop.
We only have it when iPad goes to sleep (screen goes dark but app is still running). As far as I can tell our app is not receiving any events from iOS when the iPad goes to sleep or wakes back up. Once this has all happened and the game has no sound, but exiting and restarting makes it work again.
We are getting an activate event from the native application object when iPad is woken up, I'm also checking (just because it sounds useful) the value of SoundMixer.areSoundsInaccessible, but that's way off base. I do get a soundchannel object back when I play a sound while the problem is in effect, I just can't hear it.
We were having a similar problem with audio not playing (roughly half the time the device had been asleep), and fixed it with this:
// AudioPlaybackMode.MEDIA is the default value
SoundMixer.audioPlaybackMode = AudioPlaybackMode.AMBIENT;
Once that was done, audio came back immediately after the app woke up.
Note that AMBIENT's behaviour depends on whether the microphone is being used.
I have a timer in my app, and I want it to appear to be running while my app is on the background. I'd like that if the user presses the home button when the timer shows, for instant "01:11:11" and then goes back to the app and it becomes visible to him 10 minutes later, to see the timer as "01:01:11", however I get a split second where it shows the last state when the app went to the background ("01:11:11") before it starts updating from the correct time.
I assumed that I could correct this by updating the state of my timer in "applicationDidBecomeActive" and it did work on my simulator in Xcode but not on my Ipad.
I'm using cocos2d for my drawing and this is what I'm doing in my applicationDidBecomeActive:
CCScene *s=[director_ runningScene];
GameLayer *l=[(GameLayer*)[s getChildByTag:GAME_LAYER_TAG];
if (l!=nil) [l myUpdate];
I don't think it's relevant to the problem though because myUpdate does get called but I still have that split second glitch on my Ipad, as if it starts back from its last state no matter what.
In apples clock app, in applicationDidEnterBackground it hides the timer text, so that when the app comes into the foreground you see a blank UI for the split second where your app is loading the new timer data in the UI. Also, you may want to call some of your applicationDidBecomeActive code in applicationWillEnterForeground, which is called first. But keep in mind, applicationWillEnterForeground is not called when the app first launches.
There will always be a delay between when your app comes into the foreground, and when the UI updates. Theres no way to fix that, so you might as well use what apple uses to get around the issue.
Well I tried to hide my UI in both applicationWillResignActive and applicationDidEnterBackground. Since applicationWillResignActive is called first and before going into preview (double click on HOME) it causes a "not so pretty" preview but I thought at least it would solve my original problem. It didn't (not, on my IPad). It looks like the system takes the screen shot even before applicationWillResignActive.
I checked the timer in the official clock app and I see the clock is updating even when the app is in the background (in preview), so they "cheat" anyway...
I am creating player application, which is playing audio streams through internet. I want to add alarm functionality in my app - in particular time my player begins to play audio stream, I am trying to use UILocalNotification mechanism. But I've difficulties with it when my application in background mode, I can't call 'play' method, when notification is receiced (can't without user interaction). May be it is impossible?
But I bought this application:
http://itunes.apple.com/us/app/radio-alarm-clock-mp3-radio/id380271167?mt=8
And it seems like radio can start playing when local notification is received. Alarm can start playing radio when my app is in background mode.
Earlier I was trying to use NSTimer for this, but when my app goes to background, timer stops. If I use beginBackgroundTaskWithExpirationHandler: it works only 10 minutes. My app has special flag in plist, what is is audio application, and can playing music in background. In this case timers are working. But if I stop playing and go to background, timer is not working.
When I use \Radio Alarm Clock' application, I hear 'white noise' from dinamic, when music in not playing. May be it is the secret of this application?
Can you help me with my problem? Thanks.
maybe it's too late.
I had a look to the app you've mentioned at http://itunes.apple.com/us/app/radio-alarm-clock-mp3-radio/id380271167?mt=8 and yes, I think you are absolutely right, the only way to achieve that the application remains active while in background is to play a fake sound while it is in the background, which should be prohibited by Apple.
I've also seen that they don't use the remote iPod control, and this was strange at a first look.
At the end my opinion is that they do the following:
Avoid the call to beginReceivingRemoteControlEvents which allows to activate the iPod controls while in background (in fact they don't have it)
In this way, the status bar doesn't show the play icon while
the app plays audio
When the app goes in background, it probably plays a no sound periodically (once every 10 secs for example), in this way the app remains active
I saw that they also avoided to manage interruptions, for example in case another app is in foreground and plays music. Again Apple should have rejected the app for that reason, cos it is against the rules to follow while in background, but maybe they didn't see it during the acceptance tests.
So my interpretation is that they have intentionally missed to activate the iPod controls, just to avoid to show the play icon in the status bar while in background. In this way, the users are unaware that the app is active and is doing something strange after they close it.
In addition you can see that the app doesn't interrupt when another app plays in foreground a sound or audio, because otherwise they risk that the app doesn't restart on time when the alarm shpould fire.
That's just my idea of how they do that, and I think this is the only way for an audio app on iOS to remain active while it is in background and is supposed to be halted (well, in case Apple doesn't see the trick).
Have you tried adding this to appdelegate.m
- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
// Call your method in here.
}
if you have can you add code for us to see what your doing.