Is there a way to differentiate when a user is exiting an app because he/she pressed the home button or because it's receiving a phone call? in iOS 4.0 the app doesn't quit if the user answers a call but it does in 3.x.
I'd like to save my app state if the user is interrupted by a call or any other phone event but not if the user exits the app by pressing the home button.
Any advice??
The following application delegate methods get called in different situations:
applicationWillTerminate - user pressed "home" button and application is about to exit
applicationWillResignActive - user got incoming call or sms alert. if he decides to accept the call the application will quit
applicationDidBecomeActive - user ignored incoming call
applicationDidEnterBackground - user pressed "home" button and application went to background mode - applicable for platforms that support multitasking
So it seems you need to use applicationWillResignActive: method in app delegate to distinguish between your two cases
Related
How to know the termination of app?
I added this code in viewDidLoad
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationWillTerminate:) name:UIApplicationWillTerminateNotification
object : nil];
and if the app ends, it will notify me of termination.
- (void)applicationWillTerminate:(NSNotification*) notif{
NSLog(#"program will end");
}
But it doesn't work...
I terminated the app, by clicking home button and pressing home button in 2sec, followed by clicking app icon's '-'button.
I want to be notified of the termination of app.
And also intereseted in what function to be called when the app terminates.(is it viewDidLoad?)
And the termination of app by clicking the '-'button is to send the app SIGKILL?
I terminated the app, by clicking home button and pressing home button in 2sec, followed by clicking app icon's '-'button.
If you press the home button, your app will be sent to the background. When you then kill it (by pressing the - button), it likely does not get the notification because it is not running anymore.
applicationWillTerminate is called on iOS < 4.0, when no multitasking (background) is available or when UIApplicationExitsOnSuspend is set in the info.plist file.
On iOS 4.x, when your app is sent to the background, it receives applicationWillEnterForeground:. Look at the UIApplicationDelegate Protocol Reference for more info:
You should use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
Keep in mind that you need to do this both in applicationWillEnterForeground and applicationWillTerminate if you also support iOS < 4
Have a look also at this post from S.O.
That should work, did you try adding logging into the application delegate method applicationWillTerminate: method too?
Edit:
For iOS 4+ devices, you need to do whatever work for shutdown in applicationWillEnterBackground instead... that always gets called as you are being suspended and is the right time to do final work.
you should implement applicationDidEnterBackground and do any preparation for termination there. If your app is terminated in the background, you will receive no other notification.
I would like to schedule a local notification as soon as the user hits the home button.
Which App delegate method should I use in this case :
applicationWillResignActive
applicationDidEnterBackground
applicationWillTerminate
Well I guess I shouldn't use the third one, but what is the difference between the first two ?
Is there any way to distinguish getting interrupted by a phone call/other notification and actually pressing the home button ?
Thanks in advance.
To schedule local notification you shold use applicationDidEnterBackground instead of using applicationWillResignActive because applicationWillResignActive call every time when app get some specific interruption line phone call, sms. You want to schedule notification when user press home button and in this case applicationDidEnterBackground is the appropriate place to do this.
One thing that should be remember before using applicationDidEnterBackground is that this delegate has approximately five seconds to perform any task, if any task in this delegate will take more time then os will terminate your app. You can also request for additional time for execution by using beginBackgroundTaskWithExpirationHandler and then use a secondary thread to perform a task. For more detail about application delegates follow the links -
http://developer.apple.com/library/ios/#documentation/uikit/reference/UIApplicationDelegate_Protocol/Reference/Reference.html
http://www.cocoanetics.com/2010/07/understanding-ios-4-backgrounding-and-delegate-messaging/
You should use applicationDidEnterBackground.
applicationWillResignActive gets called anytime your app is interrupted such as a phone call or SMS message. In this case if the user ignores these then your app will keep running in the foreground.
applicationDidEnterBackground only gets called when your app actually goes to the background.
You should do this in applicationDidEnterBackground:
applicationWillTerminate will not be
called when the user hits the home
button. With app switching this is
only sent when the user explicitly
quits the app or possibly in low
memory situations.
applicationWillResignActive is
additionally called when the app is
briefly interrupted, say by an SMS or
phone call alert. (Though if the user
then switches to Messages or Phone
app your app will eventually get a
applicationDidEnterBackground
message).
So it sounds like you're specifically interested in the point when the user taps the home button and the app goes to the background. applicationDidEnterBackground is the place.
You could also always schedule the local notification and only respond to it if the app isn't running when it occurs. Not better necessarily, just an option to consider.
I am wanting to save some app state data for when the user is quitting the app. I am thinking that I should be using the applicationWillTerminate method inside of my appDelegate, but when I try and do anything there, it's not doing anything:
- (void) applicationWillTerminate:(UIApplication *)application {
NSLog(#"test");
}
When I run my app, and do some stuff, and hit the home button to quit the app, nothing comes over the console...
Do I have to implement the applicationWillTerminate method in the appDelegate? The user of my app will most likely be in a Reader view when they leave, is there anyway to implement the app will close method there?
see this link iPhone simulator and applicationWillTerminate() for older iOS versions;
but remember the Home button does not necessarily terminate the application is ios4... you should use applicationDidEnterBackground but would suggest both places applicationWillTerminate and applicationDidEnterBackground
Adding the UIApplicationExitsOnSuspend key to your application’s Info.plist file and setting its value to YES will make you application quit when you hit the home button, even on iOS4
In iOS 4, the applicationWillTerminate: method is only called if you opt out of the background execution model. In the standard iOS 4 application lifecycle, applications are suspended (not terminated) when the home button is pressed. Your application delegate will receive an applicationWillResignActive: message followed by an applicationDidEnterBackground: message. The applicationDidEnterBackground: method is a good place to save user data.
I have an application wherein when the user taps iPhone's central button, the application is sent to background, but I want it to be closed.
I can hand event and close it, but may be there is some configuration setting to deny running in the background?
Thank you
If you want your app to terminate when the user presses the home button, set the value of UIApplicationExitsOnSuspend to YES in your app's Info.plist file. If you do this, when the user taps the home button the applicationWillTerminate: method of your app delegate will be called and then your application will terminate.
I want to detect application states and send it to the server. In the new OS4, with multitasking there are some methods available to help detecting the states:
application:didFinishLaunchingWithOptions:
applicationDidBecomeActive:
applicationWillResignActive:
applicationDidEnterBackground:
applicationWillEnterForeground:
applicationWillTerminate:
I read that now, we have to use applicationDidEnterBackground instead of applicationWillTerminate. My problem is that i need them both.
When the user send the app to the background, it has the state sleep. But when the user close the app ( from the multitask bar ) the state is closed. So i need to detect both, when the user send the app to the background and when the user ( or the system ) close it.
Is there anyway or workaround to make this?
I try subscribing to UIApplicationWillTerminateNotification but it doesn´t work.
Thanks in advice.
The application will quit notification is no longer fired on iOS 4 (as I am led to believe).
When the user hits the home button, the app is sent to the background, and you will get the did enter background notification. But when a user closes the app from the multitask bar, or if the system closes it, the app is sent a SIGKIL message and quits immediately, firing no notifications or delegate methods.