I am using Avplayer to show video clips and when i go back (app in background) video stop. How can i keep playing the video?
I have search about background task & background thread ,IOS only support music in background (Not video)
http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/ManagingYourApplicationsFlow/ManagingYourApplicationsFlow.html
here is some discussion about play video in background
1) https://discussions.apple.com/thread/2799090?start=0&tstart=0
2) http://www.cocoawithlove.com/2011/04/background-audio-through-ios-movie.html
But there are many apps in AppStore, that play video in Background like
Swift Player : https://itunes.apple.com/us/app/swift-player-speed-up-video/id545216639?mt=8&ign-mpt=uo%3D2
SpeedUpTV : https://itunes.apple.com/ua/app/speeduptv/id386986953?mt=8
This method supports all the possibilities:
Screen locked by the user;
List item
Home button pressed;
As long as you have an instance of AVPlayer running iOS prevents auto lock of the device.
First you need to configure the application to support audio background from the Info.plist file adding in the UIBackgroundModes array the audio element.
Then put in your AppDelegate.m into
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions:
these methods
[[AVAudioSession sharedInstance] setDelegate: self];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
and #import < AVFoundation/AVFoundation.h >
Then in your view controller that controls AVPlayer
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];
}
and
- (void)viewWillDisappear:(BOOL)animated
{
[mPlayer pause];
[super viewWillDisappear:animated];
[[UIApplication sharedApplication] endReceivingRemoteControlEvents];
[self resignFirstResponder];
}
then respond to the
- (void)remoteControlReceivedWithEvent:(UIEvent *)event {
switch (event.subtype) {
case UIEventSubtypeRemoteControlTogglePlayPause:
if([mPlayer rate] == 0){
[mPlayer play];
} else {
[mPlayer pause];
}
break;
case UIEventSubtypeRemoteControlPlay:
[mPlayer play];
break;
case UIEventSubtypeRemoteControlPause:
[mPlayer pause];
break;
default:
break;
}
}
Another trick is needed to resume the reproduction if the user presses the home button (in which case the reproduction is suspended with a fade out).
When you control the reproduction of the video (I have play methods) set
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(applicationDidEnterBackground:) name:UIApplicationDidEnterBackgroundNotification object:nil];
and the corresponding method to be invoked that will launch a timer and resume the reproduction.
- (void)applicationDidEnterBackground:(NSNotification *)notification
{
[mPlayer performSelector:#selector(play) withObject:nil afterDelay:0.01];
}
Its works for me to play video in Backgorund.
Thanks to all.
If you try to change the background mode:
Sorry, App store wont approve it.MPMoviePlayerViewController playback video after going to background for youtube
In my research, someone would take the sound track out to play in te background when it goes into background as the video would be pause and get the playbacktime for resume playing when go into foreground
It is not possible to play background music/video using Avplayer. But it is possible using
MPMoviePlayerViewController. I have done this in one of my app using this player & this app
is run successfully to appstore.
Try with this snippet, I've already integrated this with my app & it's being useful for me..hope this will work for you!!
Follow the steps given below:
Add UIBackgroundModes in the APPNAME-Info.plist, with the selection
App plays audio
Then add the AudioToolBox framework to the folder frameworks.
In the APPNAMEAppDelegate.h add:
-- #import < AVFoundation/AVFoundation.h>
-- #import < AudioToolbox/AudioToolbox.h>
In the APPNAMEAppDelegate.m add the following:
// Set AudioSession
NSError *sessionError = nil;
[[AVAudioSession sharedInstance] setDelegate:self];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:&sessionError];
/* Pick any one of them */
// 1. Overriding the output audio route
//UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
//AudioSessionSetProperty(kAudioSessionProperty_OverrideAudioRoute,
sizeof(audioRouteOverride), &audioRouteOverride);
========================================================================
// 2. Changing the default output audio route
UInt32 doChangeDefaultRoute = 1;
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(doChangeDefaultRoute), &doChangeDefaultRoute);
into the
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
but before the two lines:
[self.window addSubview:viewController.view];
[self.window makeKeyAndVisible];
Enjoy Programming!!
Swift version for the accepted answer.
In the delegate:
AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil)
AVAudioSession.sharedInstance().setActive(true, error: nil)
In the view controller that controls AVPlayer
override func viewDidAppear(animated: Bool) {
UIApplication.sharedApplication().beginReceivingRemoteControlEvents()
self.becomeFirstResponder()
}
override func viewWillDisappear(animated: Bool) {
mPlayer.pause()
UIApplication.sharedApplication().endReceivingRemoteControlEvents()
self.resignFirstResponder()
}
Don't forget to "import AVFoundation"
In addition to fattomhk's response, here's what you can do to achieve video forwarding to the time it should be after your application comes in foreground:
Get currentPlaybackTime of playing video when go to background and store it in lastPlayBackTime
Store the time when application goes to background (in userDefault probably)
Again get the time when application comes in foreground
Calculate the duration between background and foreground time
Set current playback time of video to lastPlayBackTime + duration
If you are Playing video using WebView you can handle using javascript to play video on background.
strVideoHTML = #"<html><head><style>body.........</style></head> <body><div id=\"overlay\"><div id=\"youtubelogo1\"></div></div><div id=\"player\"></div> <script> var tag = document.createElement('script'); tag.src = \"http://www.youtube.com/player_api\"; var firstScriptTag = document.getElementsByTagName('script')[0]; firstScriptTag.parentNode.insertBefore(tag, firstScriptTag); var player; events: { 'onReady': onPlayerReady, } }); } function onPlayerReady(event) { event.target.playVideo(); } function changeBG(url){ document.getElementById('overlay').style.backgroundImage=url;} function manualPlay() { player.playVideo(); } function manualPause() { player.pauseVideo(); } </script></body> </html>";
NSString *html = [NSString stringWithFormat:strVideoHTML,url, width, height,videoid;
webvideoView.delegate = self;
[webvideoView loadHTMLString:html baseURL:[NSURL URLWithString:#"http://www.your-url.com"]];
On view diappear call
strscript = #"manualPlay();
[webvideoView stringByEvaluatingJavaScriptFromString:strscript];
I'd like to add something that for some reason ended up being the culprit for me. I had used AVPlayer and background play for a long time without problems, but this one time I just couldn't get it to work.
I found out that when you go background, the rate property of the AVPlayer sometimes seems to dip to 0.0 (i.e. paused), and for that reason we simply need to KVO check the rate property at all times, or at least when we go to background. If the rate dips below 0.0 and we can assume that the user wants to play (i.e. the user did not deliberately tap pause in remote controls, the movie ended, etc) we need to call .play() on the AVPlayer again.
AFAIK there is no other toggle on the AVPlayer to keep it from pausing itself when app goes to background.
I am creating a local UILocalNotification and displaying it to the user as a banner. Is it possible to set it up so that when the user taps it and returns to the app, the app will receive some kind of data on the specific kind of notification it was? I want to open a specific view controller in the app. I think the best way would be to essentially send a URL to the app, or is there a way to get access to the UILocalNotification so that I can test which kind is was and do the right action?
To get data from the local NSUserNotification that is passed to an iOS app, all that you need to do is implement the following method: - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification.
The problem is, this is called both when a local notification is posted when the app is in the background (i.e. when the user taps on the notification and then returns to the app), and also if the app is in the foreground at the time when the local notification fires (it is on a timer, after all). So how should one figure out if the notification was fired when the app was in the background or foreground? It's pretty simple. Here's my code:
- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
UIApplicationState state = [application applicationState];
if (state == UIApplicationStateInactive) {
// Application was in the background when notification was delivered.
} else {
// App was running in the foreground. Perhaps
// show a UIAlertView to ask them what they want to do?
}
}
At this point you can handle the notification based on notification.userInfo, which holds a NSDictionary.
ust implement the NSUserNotificationCenterDelegate and define this method:
- (void)userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification
Example:
This is what I did in a "notifier" application.
- (void) userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification
{
NSRunAlertPanel([notification title], [notification informativeText], #"Ok", nil, nil);
}
- (void) userNotificationCenter:(NSUserNotificationCenter *)center didDeliverNotification:(NSUserNotification *)notification
{
notifications=nil;
[tableView reloadData];
[center removeDeliveredNotification: notification];
}
When the notification is activated (click by the user) I just inform the user with a panel (I could use a hud window).In this case I immediately remove the delivered notification, but this is not what happens usually.The notification could stay there some time and be removed after 1/2 hours (it depends on the application that you are developing).
1 - Define some class in your project to implement NSUserNoficationCenterDelegate protocol (documented here)
#interface someObject : NSObject <NSUserNotificationCenterDelegate>
{
- (void)userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification;
}
2 - Set an instance of the object defined #1 as the delegate of default notification center.
[[NSUserNotificationCenter defaultNotificationCenter] setDelegate: someObject];
Now you will get called on didActivateNotification any time the user taps/clicks on the notification. You will have the original notification you created. So any information that you need should be available to you.
If you want/need special information (other than notification title, message, etc) you will probably need to set additional application specific information in your notification before you schedule it to be sent. For example:
NSUserNotification* notification = [[NSUserNotification alloc] init];
NSDictionary* specialInformation = [NSDictionary dictionaryWithObjectsAndKeys: #"specialValue", #"specialKey", nil];
[notification setUserInfo:specialInformation];
I'm trying to create an iPad app where i need to playback a quicktime movie which contains some chapter markers. When each marker is reached i need a small overlay to be shown on top of the video.
Is there a way to trigger an event/function each time a marker is reached? And if so, how?
I'm not interested in having to develop an entire movieplayer with codec handling from scratch, since this is out of my comfortzone - So I'm hoping this is possible using MPMoviePlayer or something similar.
Any help is greatly appreciated! :)
Register to receive the following notification:
#define MPAVControllerTimeDidJumpNotification #"MPAVControllerTimeDidJumpNotification"
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(handleTimeChanged:) name:MPAVControllerTimeDidJumpNotification object:nil];
-(void)handleTimeChanged:(NSNotification *)notification
{
static int i = 0;
NSDictionary * userInfo = notification.userInfo;
int lastPositionInSeconds = [[userInfo valueForKey:#"MPAVControllerTimeParameter"] intValue];
if(lastPositionInSeconds > markers[i])
{
i++;
[self showOverlay: i];
}
}
Also register to receive MPMoviePlayerPlaybackDidFinishNotification notification to stop listening for the MPAVControllerTimeDidJumpNotification notification.
I've heavily researched for a proper solution but it didn't work out functional:
My iPhone app updates data via NSURL requests on user demand. Each file loaded online is only 1.5k in size but one update can consist of 400 of such files. So I do the download stuff in a separate thread which is cancelable and during the update there is an UIAlertView with process indication and cancel button. The thing may run 1...3 minutes, so it can exceed the timeout the device is staying alive or other things happen and my app will go background.
When I do nothing when applicationDidEnterBackground is called, I realize that my app is suspended and also the worker thread. It wakes up and continues work when the app is in foreground again. So far so good. I get into trouble when I press the cancel button after being in foreground again - then the thread reacts as being cancelled (as it should) but immediately runs again and crashes at the end (with error codes somewhere deep in Apple frameworks). It works perfectly to cancel the thread as long as the app keeps staying in foreground - so my idea is to stop/cancel it when applicationDidEnterBackground is entered. I've tried some things to do so but each attempt ends in the fact that the worker thread is suspended at that moment applicationDidEnterBackground is called, so I can't cancel the thread and wait for that. One example I tried is this:
diagView* viewDiagCtrl = startDiag.diagViewControl;
if (viewDiagCtrl != nil && viewDiagCtrl.actionThread != nil)
{
// UIBackgroundTaskIdentifier bgTask is instance variable
NSAssert(self->bgTask == UIBackgroundTaskInvalid, nil);
bgTask = [application beginBackgroundTaskWithExpirationHandler:
^{
dispatch_async(dispatch_get_main_queue(),
^{
NSLog(#"stopping actions definitely");
[viewDiagCtrl stopBackGroundActivity:self];
[application endBackgroundTask:self->bgTask];
self->bgTask = UIBackgroundTaskInvalid;
});
}];
dispatch_async(dispatch_get_main_queue(),
^{
// Start with 10ms time boxes
NSTimeInterval ti = 0.01;
while ([application backgroundTimeRemaining] > 1.0)
{
if (![viewDiagCtrl.actionThread isExecuting])
break;
NSDate* date = [NSDate dateWithTimeIntervalSinceNow:ti];
// Let the current run-loop do it's magif for one time-box.
[[NSRunLoop currentRunLoop] runMode: NSRunLoopCommonModes
beforeDate: date];
// Double the time box, for next try, max out at 1000ms.
ti = MIN(1.0, ti * 2);
}
[viewDiagCtrl stopBackGroundActivity:self];
[application endBackgroundTask:self->bgTask];
self->bgTask = UIBackgroundTaskInvalid;
});
}
I'm not experienced with the whole queue stuff and found such a construct somewhere. I assume that all things dispatched work in the main thread and the worker thread remains suspended so that I don't have any chance to cancel it. Any ideas to come around with that?
I've also read about attempts to do everything without multithreading - but I don't really appreciate that.Is there maybe some useful link to handle the "go background" situation properly?
You can wrap your thread work in the background thread like:
...
[self performSelectorInBackground:#selector(backgroundThread)
withObject:nil];
...
-(void)backgroundThread
{
// do a download once a minute in a background thread - dont let the system suspend us
while(true)
{
BOOL expire = NO;
bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{expire = YES;}];
while(!downloadComplete && !expire)
{
//do your multiple file downloads here;
}
[[UIApplication sharedApplication] endBackgroundTask:bgTask];
[NSThread sleepForTimeInterval:60];
}
}
What this will do is continue the task in progress which will continue when the app is backgrounded - I do this is several places in my heavily threaded/network intensive app.
AFAIK: You don't have to wait until the app is being backgrounded to call beginBackgroundTask - you should call it any time your app has a function it needs to complete without being interrupted/suspended.
I also use NSURLRequest with:
[request setNetworkServiceType:NSURLNetworkServiceTypeVoIP];
(and use the voip background mode in the supportedbackgroundmodes flag)
How can I detect lock/unlock events on the iPhone? Assuming it's only possible for jailbroken devices, can you point me to the correct API?
By lock events, I mean showing or hiding the Lock Screen (which might need a password to unlock, or not).
You can use Darwin notifications, to listen for the events. From my testing on a jailbroken iOS 5.0.1 iPhone 4, I think that one of these events might be what you need:
com.apple.springboard.lockstate
com.apple.springboard.lockcomplete
Note: according to the poster's comments to a similar question I answered here, this should work on a non-jailbroken phone, too.
To use this, register for the event like this (this registers for just the first event above, but you can add an observer for lockcomplete, too):
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
(void*)self, // observer (can be NULL)
lockStateChanged, // callback
CFSTR("com.apple.springboard.lockstate"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
where lockStateChanged is your event callback:
static void lockStateChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo) {
NSLog(#"event received!");
if (observer != NULL) {
MyClass *this = (MyClass*)observer;
}
// you might try inspecting the `userInfo` dictionary, to see
// if it contains any useful info
if (userInfo != nil) {
CFShow(userInfo);
}
}
The lockstate event occurs when the device is locked and unlocked, but the lockcomplete event is only triggered when the device locks. Another way to determine whether the event is for a lock or unlock event is to use notify_get_state(). You'll get a different value for lock vs. unlock, as described here.
Round about answer:
Application will resign active gets called in all sorts of scenarios... and from all my testing, even if your application stays awake while backgrounded, there are no ways to determine that the screen is locked (CPU speed doesn't report, BUS speed remains the same, mach_time denom / numer doesn't change)...
However, it seems Apple does turn off the accelerometer when the device is locked... Enable iPhone accelerometer while screen is locked
(tested iOS4.2 on iPhone 4 has this behavior)
Thus...
In your application delegate:
- (void)applicationWillResignActive:(UIApplication *)application
{
NSLog(#"STATUS - Application will Resign Active");
// Start checking the accelerometer (while we are in the background)
[[UIAccelerometer sharedAccelerometer] setDelegate:self];
[[UIAccelerometer sharedAccelerometer] setUpdateInterval:1]; // Ping every second
_notActiveTimer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:#selector(deviceDidLock) userInfo:nil repeats:NO]; // 2 seconds for wiggle
}
//Deprecated in iOS5
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
{
NSLog(#"STATUS - Update from accelerometer");
[_notActiveTimer invalidate];
_notActiveTimer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:#selector(deviceDidLock) userInfo:nil repeats:NO];
}
- (void)deviceDidLock
{
NSLog(#"STATUS - Device locked!");
[[UIAccelerometer sharedAccelerometer] setDelegate:nil];
_notActiveTimer = nil;
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
NSLog(#"STATUS - Application did become active");
[[UIAccelerometer sharedAccelerometer] setDelegate:nil];
[_notActiveTimer invalidate];
_notActiveTimer = nil;
}
I know... It's kind of a hack, but it has worked like a charm for me so far. Please update if you see any issues that prevent this from working.
There is a prettier way of telling apart task switching and screen locking-originated applicationWillResignActive: callbacks which doesn't even involve undocumented features such as the accelerometer state.
When the app is moving to the background, the app delegate is first sent an applicationWillResignActive:, then an applicationDidEnterBackground:. When the app is interrupted by pressing the Lock button or by an incoming phone call, the latter method is not called. We can use this information to distinguish between the two scenarios.
Say you want to be called back in the screenLockActivated method if the screen gets locked. Here's the magic:
- (void)applicationWillResignActive:(UIApplication*)aApplication
{
[self performSelector:#selector(screenLockActivated)
withObject:nil
afterDelay:0];
}
- (void)applicationDidEnterBackground:(UIApplication*)aApplication
{
[NSObject cancelPreviousPerformRequestsWithTarget:self];
}
- (void)screenLockActivated
{
NSLog(#"yaay");
}
Explanation:
By default, we assume that every call to applicationWillResignActive: is because of an active->inactive state transition (as when locking the screen) but we generously let the system prove the contrary within a timeout (in this case, a single runloop cycle) by delaying the call to screenLockActivated. In case the screen gets locked, the system finishes the current runloop cycle without touching any other delegate methods. If, however, this is an active->background state transition, it also invokes applicationDidEnterBackground: before the end of the cycle, which allows us to simply cancel the previously scheduled request from there, thus preventing it from being called when it's not supposed to.
Enjoy!
As of the time of writing there are two fairly reliable ways to detect device locking:
Data Protection
By enabling the Data Protection entitlement your app can subscribe to the applicationProtectedDataWillBecomeUnavailable: and applicationProtectedDataDidBecomeAvailable: notifications to determine with high probability when a device that uses passcode/TouchID Authentication is locked/unlocked. To determine if a device uses a passcode/TouchID LAContext can be queried.
Caveats: This method relies on the "protected data becoming unavailable" coinciding with the phone being locked. When the phone is using TouchID and the sleep/lock button is pressed then the phone is locked, protected data becomes unavailable, and a passcode will immediately be required to unlock it again. This means that protected data becoming unavailable essentially indicates that the phone has been locked. This is not necessarily true when someone is using just a passcode since they can set the "requires passcode" time to anywhere from immediately to something like 4 hours. In this case the phone will report being able to handle protected data but locking the phone will not result in protected data becoming unavailable for quite some time.
Lifecycle Timing
If your app is in the foreground there will be a noticeable change in time difference between the two lifecycle events UIApplicationWillResignActiveNotification and UIApplicationDidEnterBackgroundNotification depending on what triggers them.
(This was tested in iOS 10 and may change in future releases)
Pressing the home button results in a significant delay between the two (even when the Reduced Motion setting is enabled):
15:23:42.517 willResignActive
15:23:43.182 didEnterBackground
15:23:43.184 difference: 0.666346
Locking the device while the app is open creates a more trivial (<~0.2s) delay between the two events:
15:22:59.236 willResignActive
15:22:59.267 didEnterBackground
15:22:59.267 difference: 0.031404
in iOS 8, you lock the screen or push the home button, all of those make app push in background, but you don't know which operator result in this. My solution same with Nits007ak,use notify_register_dispatch to get state.
#import <notify.h>
int notify_token
notify_register_dispatch("com.apple.springboard.lockstate",
¬ify_token,
dispatch_get_main_queue(),
^(int token)
{
uint64_t state = UINT64_MAX;
notify_get_state(token, &state);
if(state == 0) {
NSLog(#"unlock device");
} else {
NSLog(#"lock device");
}
}
);
As long as the app is running, in foreground or background. not suspend, you can get this event.
And you can use notify_token as parameter of notify_get_state to get current state anywhere, this is useful when you want know the state and the screen state don't change.
If passcode is set, you can use these event in AppDelegate
-(void)applicationProtectedDataWillBecomeUnavailable:(UIApplication *)application
{
}
- (void)applicationProtectedDataDidBecomeAvailable:(UIApplication *)application
{
}
Just import #import notify.h before using this code. enjoy!!
-(void)registerAppforDetectLockState {
int notify_token;
notify_register_dispatch("com.apple.springboard.lockstate", ¬ify_token,dispatch_get_main_queue(), ^(int token) {
uint64_t state = UINT64_MAX;
notify_get_state(token, &state);
if(state == 0) {
NSLog(#"unlock device");
} else {
NSLog(#"lock device");
}
NSLog(#"com.apple.springboard.lockstate = %llu", state);
UILocalNotification *notification = [[UILocalNotification alloc]init];
notification.repeatInterval = NSDayCalendarUnit;
[notification setAlertBody:#"Hello world!! I come becoz you lock/unlock your device :)"];
notification.alertAction = #"View";
notification.alertAction = #"Yes";
[notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
notification.soundName = UILocalNotificationDefaultSoundName;
[notification setTimeZone:[NSTimeZone defaultTimeZone]];
[[UIApplication sharedApplication] presentLocalNotificationNow:notification];
});
}
From a lot of trial and error, discovered monitoring the blank screen, lock complete and lock state events gives a consistent lock screen indicator. You'll need to monitor a state transition.
// call back
void displayStatusChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo)
{
// notification comes in order of
// "com.apple.springboard.hasBlankedScreen" notification
// "com.apple.springboard.lockcomplete" notification only if locked
// "com.apple.springboard.lockstate" notification
AppDelegate *appDelegate = CFBridgingRelease(observer);
NSString *eventName = (__bridge NSString*)name;
NSLog(#"Darwin notification NAME = %#",name);
if([eventName isEqualToString:#"com.apple.springboard.hasBlankedScreen"])
{
NSLog(#"SCREEN BLANK");
appDelegate.bDeviceLocked = false; // clear
}
else if([eventName isEqualToString:#"com.apple.springboard.lockcomplete"])
{
NSLog(#"DEVICE LOCK");
appDelegate.bDeviceLocked = true; // set
}
else if([eventName isEqualToString:#"com.apple.springboard.lockstate"])
{
NSLog(#"LOCK STATUS CHANGE");
if(appDelegate.bDeviceLocked) // if a lock, is set
{
NSLog(#"DEVICE IS LOCKED");
}
else
{
NSLog(#"DEVICE IS UNLOCKED");
}
}
}
-(void)registerforDeviceLockNotif
{
// screen and lock notifications
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.hasBlankedScreen"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.lockcomplete"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.lockstate"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
}
To have the screen lock indicators run in the background, you need to implement background processing calling the following upon app launching.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.backgroundTaskIdentifier =
[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
[[UIApplication sharedApplication] endBackgroundTask:self.backgroundTaskIdentifier];
}];
[self registerforDeviceLockNotif];
}
If your app is running and the user locks the device your app delegate will receive a call to 'application Will Resign Active:'. If your app was running when locked, it will receive a call to 'application Did Become Active:' when the device is unlocked. But you get the same calls to your app if the user gets a phone call and then chooses to ignore it. You can't tell the difference as far as I know.
And if your app wasn't running at any of these times there is no way to be notified since your app isn't running.
The simplest way to get screen lock and unlock events are by adding event observers using NSNotificationCenter in your viewcontroller. I added the following observer in the viewdidload method. This is what i did:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationEnteredForeground:)
name:UIApplicationWillEnterForegroundNotification
object:nil];
Then I added the following selector to the viewcontroller. This selector will get called when the screen is unlocked.
- (void)applicationEnteredForeground:(NSNotification *)notification {
NSLog(#"Application Entered Foreground");
}
If you want to detect the event when screen gets locked, you can replace UIApplicationWillEnterForegroundNotification with UIApplicationDidEnterBackgroundNotification.