I would like to perform some UI Operations before an application goes into the background ..
UIApplicationDidEnterBackgroundNotification
just doesn't cut it ..
I have a MPMoviePlayerController streaming an m3u8 file and i need to pause this video before the application goes into the background mainly because ..
If i do tap on the home button while the video is playing and come into the foreground again ..
The buffered stream of the video is lost and the video plays in a buggy manner and strangely this happens only on iPhone and not iPad ..
so i am hoping to work around this and pause the video before it goes into the background ..
The UIApplicationWillResignActiveNotification seems exactly what you're looking for.
ref: http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIApplication_Class/Reference/Reference.html
Please take a look at this Application Delegate
Or you can even perform task for a finite time after your application enter to background
Check out here
Related
I'm playing a silent music with AVAudioPlayer when user locks the screen, so that my timers won't stop.
However, when I play an iPod music with [MPMusicPlayerController applicationMusicPlayer], AVAudioPlayer stops,without receiving any call back.
Is there any way so that I can start [MPMusicPlayerController applicationMusicPlayer] playing without stoping AVAudioPlayer playing?
EDIT:
Thanks guys, this is the app I'm working on:
It is an Alarm app, this app allows user to lock screen while app is running,and when it is the time of the alarm, app can play iPod music to wake the user.Local notification can not use iPod music as alert sound, so I have to keep the app running while screen is locked.
If user quit the app, it will use local notification as alarm, whose sound is limited to files in bundle.
I can't use UILocalNotification as timer since when in screen locked status（in UIApplicationStatusInactive), app can't receive local notification generated by the system.
Apple has architected their backgrounding system to really limit things like this from happening. Essentially, there is no way for the you to keep the application running in the background unless it needs to be there. If you explain what you are trying to accomplish, maybe a better solution can be found but as good practice, never use random backgrounding methods to do other things. I am assuming that you might be using the faint music as a way to show something custom on the main screen, this is not a good idea.
Your app will get rejected if you play a silent audio.
Also as per apple's documentation https://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/IPhoneOSClientImp/IPhoneOSClientImp.html#//apple_ref/doc/uid/TP40008194-CH103, notifications cannot have sounds (soundName) which play more than 30 seconds.
So you wont be able to release your app in the store.
I figured it out myself.
It is not calling [MPMusicPlayerController +applicationMusicPlayer] that stops AVAudioPlayer, but calling [MPMusicPlayerController -setShuffleMode:], I don't know why calling this would stop AVAudioPlayer, but it is where the problem lies in.
Thanks everyone, I think I should paste my complete code next time.
Well I am having two issues that i can't get to work, related to audio and calls.
The first one is to play a sound during a phone call. I don't want to play continuous music or stream anything, it is just a simple and short sound that the user will hear at one time during his call.
I have read some posts claiming that this is possible, and I even have an application that does so, but I can't get it to work. My app identifies the call using CTCallCenter and print the logs but never plays the sound or plays it after the app comes to foreground again. I have the .plist property of required background mode App plays audio.
The second issue, is to play the sound after some elapsed time. NSTimers doesn't work when on background mode, nor NSThread sleep on my background process or NSOperation. So how could I play this sound after say 10 seconds of the call?
Also, this behavior has to work also when the application is already on background mode. With CTCallCenter I am only getting the event when the application is interrupted from use, but I don't see any logs when i send the app to background and then begin/receive a call
.
If anyone could point me to the right direction I'll be really grateful.
I havent done this, but NSLocalNotifcation, schedule a notification to play when you app get the call to move into the background. I would expect this to work. Interested to find out if it does.
I am using MPMoviePlayerController to play streaming audio. I'm trying to get background audio working correctly. Right now, audio continues to play when you exit the app - the lock-screen and multi-tasking bar controls even work.
When a song finishes, the app is supposed to advance to the next track and play it. It works when the app is open but not when it is in the background (a song finishes but does not advance to the next track). If a song finishes and you re-open the app, however, the next song will start up immediately.
I am currently using NSNotificationCenter to keep track of when tracks end to advance to the next track (in my app delegate). Again, it works like a charm when the app is open. Is there a better way to do this to keep audio playing after a song is done?
I had this issue lately. Hope the answer helps other people.
If you have a playlist for example and want to play the next song while in background mode or lock mode add this line of code on your viewDidLoad:
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
This makes the app supports remote control events.
I am developing an iphone app which uses background audio (on an infinite loop) to continue playing after the app has entered the background.
My problem is I want to implement a "sleep timer" which stops playback after a specified period of time.
Is this possible? I have spent an hour looking for a method to do this with no avail.
EDIT: My current thought is to use a lower level API, the Audio Queue Services, and manually re-fill the queue with another instance of the loop during the AudioQueueOutputCallback. If the timer has expired I do not fill the loop. I'm assuming this should work since the documentation says audio callbacks are still fired when an app is playing multitasking background audio. Can anyone think of a better way or a reason why this wouldn't work?
While you queue sound data on the background your app remains fully functional and running as if it was in the foreground (well almost), so yes, you should just write a timer that stops the playback at a given time and it will be fired as expected.
Now to the second question: once you stop queueing things up, your app will be "frozen" until the user manually brings it to the foreground... So what you should do is start queueing audio data from the second file before the first one is done playing, and if you DO need to pause or stop, maybe a solution is to play 0 bytes (silence)?
I'm not actually sure this would be allowed in the App Store. An app is not allowed to execute at all in the background, with the exception of VoIP apps and push notifications.
I'm making a Web app (at chirpid.com) for the iPhone that plays audio files for cricket chirp identification. The user can start and stop the audio by tapping screen buttons. But if the user taps the home button while a sound file is playing, it continues to play in the background (an iOS4 feature). I want to stop the audio in this case. Is there an event or property that I can use via Javascript in Safari to determine when I have been put into the background?
You could manually trigger the "stop" button like this when closing the application.
- (void)applicationDidEnterBackground:(UIApplication *)application {
if(audioIsPlaying) {
[btnStop sendActionsForControlEvents:UIControlEventTouchUpInside];
}
}
You get 5 seconds to do anything when using the applicationDidEnterBackground: function.
That should be enough to stop the audio ;-).
I would guess you need to create a listener that listens to system events...
Perhaps you should read this book: http://books.google.com/books?id=a09NMFdA6m0C&pg=PA94&lpg=PA94&dq=iOS+home+button+event+javascript&source=bl&ots=4Nop45gmwI&sig=8mTEGQI1ym65H7XjmBSzRQ2KyMc&hl=en&ei=_qDWTrmMDsPh4QSR9I2rAQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEsQ6AEwBQ#v=onepage&q=iOS%20home%20button%20event%20javascript&f=false
iOS4 has some kind of lock function you can assign to buttons, perhaps you could tie in a script to turn down volume that way.
If you found the solution be nice and post it here for others to see.
Best of luck!