Is there any notification I can listen to that will alert me that the phone will go to sleep? I have implemented the following:
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(resignActive:)
name:UIApplicationDidEnterBackgroundNotification
object:nil];
but it seems that it's not getting triggered when the phone goes to sleep after some time of inactivity (1 min in my settings). The reason I think it's not working is that I have a timer that perform an action every second and if a certain time has passed (bigger than one minute) it issues an audio alarm. In my resignActive I invalidate my timer and that works fine when I press the home button, but not when the phone goes to sleep. It still seems to be running in the background but "at a lower speed" as the times are much longer than normal (around 10 min instead of 2 min).
Any ideas what's happening when the phone goes to sleep? I have read these two posts but it doesn't really answer my question.
What happens to an iPhone app when iPhone goes into stand-by mode?
Iphone app is delayed for 10 -15 minutes when iphone is in sleep mode
Implements those 2 methods on the UIApplicationDelegate :
- (void)applicationWillResignActive:(UIApplication *)application
- (void)applicationDidBecomeActive:(UIApplication *)application
It will be called also when a push notification from another app (or a SMS) is shown...
Related
I have created GPS base Application.
In which App logged GPS data every 1 second.
App used the NSTimer to fetch GPS data every second.
This NSTimer is start in background. The NSTimer is start when app received the silent push notification from APNS.
I have seen a problem in iOS 7 that when Phone attached with power cable at that time timer call appropriately but without attached power cable timer stops while App in background.
Any inputs to resolve this issue greatly appreciated.
An NSTimer is not guaranteed to fire if your app is not in foreground. Once you unplug the cable the system puts your app into background to save battery.
Using an NSTimer is not the supported method to get location data. Your CLLocationManager will tell its delegate when there is a new location. No need to poll it.
If you need to track geolocation in background you need to declare location updates as a background mode from the capabilities tab in Xcode 5 target settings. Otherwise your location manager will stop delivering location updates once your app is not in foreground.
There are only few use cases that you can implement for foreground. If you don't want your application to be refused within review please don't use any hacks. Of course, you can use NSTimer in background, but it must be created in thread (runloop) of background task. But this background task lives for the only certain amount of time, so your timer must fire during this period. In other words, your first goal is to create background task, and only then you can use the timer. There are few cases suitable for your purpose (that allow you to create this task): 1.Monitor significant location changes or region 2.Fetch data (iOs 7). So please refer
-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
NSLog(#"BG fetch in action");
//the only 30 sec is allowed to perform all your actions
//during this period you can each second track GPS data
[self performSelector:#selector(finishBackgroundFetch:) withObject:completionHandler afterDelay:27];
[[NSNotificationCenter defaultCenter] postNotificationName:#"StartMyGPSRoutine" object:nil];
}
-(void)finishBackgroundFetch:(void (^)(UIBackgroundFetchResult))completionHandler {
NSLog(#"BG fetch completion handler");
[[NSNotificationCenter defaultCenter] postNotificationName:#"ForceStopAnyBackgroundTaskCreatedWithStartMyGPSRoutine" object:nil];
completionHandler(UIBackgroundFetchResultNewData);
}
of your application delegate -- this will be useful in your case as well as monitor significant location changes.
You ought to put anywhere:
if ([[UIApplication sharedApplication] respondsToSelector:#selector(setMinimumBackgroundFetchInterval:)]) {
NSLog(#"Set Force BG interval to %ld", interval);
[[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:interval];
}
In my case I fetch the GPS data each 5 min so 27sec to complete this task is not so long. Anyway you can play with time intervals with XCode. Please refer Main Menu->Debug->Simulate Background Fetch
I'm writing an iPhone app. When the app is running and the iPhone is charging, there is no need to lock the iPhone. Is it possible to prevent the locking of the iPhone when the device is charging and my app is running?
You can subscribe to UIDeviceBatteryStateDidChangeNotification notification to get the moment when your iphone begins/stops to charge. Then in case iphone is charging you can set idleTimerDisabled property in UIApplication object to YES to prevent device to go to sleep:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(updateBatteryState:)
name:UIDeviceBatteryStateDidChangeNotification
object:nil];
- (void) updateBatteryState:(NSNotification*)notification{
[UIApplication sharedApplication].idleTimerDisabled =
([UIDevice currentDevice].batteryState == UIDeviceBatteryStateCharging);
}
P.S. If user decides to put device to sleep with sleep/wake button there's no way to prevent him of doing so
This is not possible with current SDK.
EDIT: hmm, haven't got the question correctly from the first read - look on other replies for correct answer; my guess was, you were asking about if it possible to prevent appearance of the sync/charge screen when connecting device via usb or to the wall outlet
I want to schedule a local notification when my previous local notification gets fired.
It should get scheduled disregarding the user taps 'View' or 'Cancel'.I am not getting proper place(delegate method)to schedule a new notification.According to Apple docs,application:(UIApplication *)application didFinishLaunchingWithOptions: can be used but it doesn't seems to be get called when application comes to foreground from background and application:(UIApplication *)application didReceiveLocalNotification: gets called only on click of 'View' and not on close.How should I do this?Any help is highly appreciated.
Yes. You are correct about the local notifications. You should click "view" to get the didReceiveLocalNotification: triggered. If you click "Cancel", you are not caring about the notificaiton. If you don't care, why should the iOS care? :-)
You are scheduling the notification. So, you know when it will be fired. Don't you? Then why wait for the first notification to be fired? Just schedule the second notification along with the first notification.
A workaround:
Local and Push Notification Programming Guide
says that only 64 local notifications are allowed per app. So, schedule the first 64 notifications initially. And when the app opens the next time, check [UIApplication sharedApplication] scheduledLocalNotifications], and schedule the next (64 - scheduledLocalNotifications) notifications.
int scheduledNotifications = [UIApplication sharedApplication] scheduledLocalNotifications];
int n = 64 - scheduledNotifications;
[self Schedule-next-n-notifications];
Note: We can't guarantee that this will work perfectly. In case, if the app opens after very long gap, for example after 1 or 2 months, some notifications would have not been scheduled at the proper time.
If a UILocalNotification fires with a sound set, and the user taps "Cancel" on the notification alert, the sound is stopped. But if the user taps "View", iOS then delivers the notification to the app and the sound keeps on playing. Is there any way to cancel this sound from the app? Canceling the notification in the app once the notification is delivered doesn't work (I didn't expect it to, the notification has already been delivered after all), and since I don't have the sound's system sound ID (and I didn't allocate it in the first place), I can't call AudioServicesDisposeSystemSoundID (can I?).
Is it possible to stop a UILocalNotification sound from playing if the user taps the Action button of the notification's alert?
It does not stop on the device too (5.1)
I have been trying to fix it but I can't figure it out.
I actually got it to stop on the simulator using this
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
UILocalNotification *localNotif = [launchOptions objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];
if (localNotif) {
[[UIApplication sharedApplication] cancelLocalNotification:localNotif];
}
return YES;
}
but It still doesn't stop on the device
Apparently the problem only exists on the simulator (iOS 4.2 sdk), not on the actual device.
It can be handled in application delegate method as follows, if the user taps the Action button of the notification's alert, then the following method will be called, there we can cancel the notification
- (void)application:(UIApplication *)app
didReceiveLocalNotification:(UILocalNotification *)notif {
[[UIApplication sharedApplication]cancelLocalNotification:notif];
}
I had the same problem when initially testing with an iPhone 4.
The problem appears to have gone away as of iOS 8 and now Local Notification Sounds stop when canceled after transitioning to the App.
iPhone4 [ iOS - 7.1.2 ] - Local Notification sound keeps playing in App no matter what
iPhone6 [ iOS - 8.1.1 ] - Local Notification sound stop when canceled programmatically
From what I can infer, it appears a fix exists somewhere in iOS 8.x
(Alas I didn't manage to find any documentation or release notes on the matter.)
The Problem becomes a non-issue for apps focusing on iOS 8
(provided you cancel the Local Notification coming in)
I have an iphone game that plays background music using AVSoundPlayer - when someone locks the iphone the music stops which is fine. But when someone unlocks it, I don't want my music to start playing again while you're staring at the "slide to unlock" screen - I want it to start playing once you've actually slid the button and the app is visible again - is there some way to detect this? (I've tried applicationDidBecomeActive but that fires when the phone is unlocked but not when your app is visible yet...)
You could try viewWillAppear.
- (void)applicationDidBecomeActive:(UIApplication *)application;
This sent when your app becomes active
Another answer on SO applicable to your question:
applicationWillTerminate works as long as I don't switch off the iPhone