When my app is run in the iPhone simulator, the delegate method
- (void)applicationWillTerminate:(UIApplication *)application
is only called the first time I hit the iPhone simulator's home button.
After the home button is pressed and the app is launched again, hitting the home button does not call the delegate method.
What is going on here? Am I misunderstanding something fundamental?
I suspect that it is being called, but that you are getting confused because after you hit the Home button in the Simulator, you've ended the current session in Xcode. You probably have an NSLog in your applicationWillTerminate: method, yes? Once you hit the Home button, NSLogs no longer show up in Xcode's run console. If you open /Applications/Console.app I expect they'll show up there.
- (void)applicationWillTerminate:(UIApplication *)application
is called when the application "terminates".
If you are using iOS then the app will NOT terminate when the home button is pressed, unless you have disabled multi-tasking for your app or the user does not have a "multi-tasking supported" device.
- (void)applicationDidEnterBackground {
is now used when the user presses the home button. Unless (as I previously said) you have disabled multi-tasking for your app or the user does not have a "multi-tasking supported" device.
Related
I have an app with multiple View Controllers. I have a Home screen with "Play / Options / etc.". When you hit Play, you navigate over to the GamePlay View Controller and start playing.
I find that if I'm in the "gameplay" VC and I hit the iPhone's Home button (leaving my app) and then re-launch my app, it puts me right back to the game screen. I'd like to force the app to start on the same "Home" screen every time is it launched.
Suggestions greatly appreciated!
Thanks,
-Ed
in your app's plist add the key UIApplicationExitsOnSuspend and set it to YES.
Your app wont be suspended and youll always start on the home screen
When you press the Home button, the application goes to background. When launched again, application just enters foreground from background. I think you can load the home screen in the following delegate method in AppDelegate
- (void)applicationWillEnterForeground:(UIApplication *)application
You can preserve the state of the game (I don't want to kill that zombie again!) in the following:
- (void)applicationDidEnterBackground:(UIApplication *)application
Hi I am new to iPhone development, I am developing a TabBar app it's contains 5 tabbar Items.
When I am close app at third TabBar viewController screen and again when I am opening app that time same third TabBar viewController screen only opening.
How to set App first screen as a default App opening Screen in iphone.
I need to set first screen as a default opening screen when ever open a app.
Could you please share your ideas here..
When you close the app, it doesn't KILL it, it just suspends it. Unless you set the option to kill it when you close it.
I suggest you read Apple Documentation For Application Flow
And possibly read the other documents Apple have provided for you there if you are new to all of this.
In your application's Info.plist, add a boolean key UIApplicationExitsOnSuspend with the value YES.
This will always exit the app (instead of running in background) when you close it. On opening app again, first view controller will appear instead of where you left it last time.
This is because you are setting your application to be run in background, so whenever you close your app the app will run in background and resume on startUp.
so just do one thing
Go to your info.plist and set value for
Application does not run in background to YES
If application is killed by default it loads all settings in Application Delegate method:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
Here you can modify your root view controller, which I presume is some kind of tab bar view controller.
So there is probably some code in that method which defines which tab to load.
However if you want to show specific tab after application enters in the foreground use Application delegate method:
- (void)applicationWillEnterForeground:(UIApplication *)application
Or
- (void)applicationDidBecomeActive:(UIApplication *)application
When exiting the app by for example pressing the home button on the iPhone the app is not terminated. Instead the execution is suspended but the app will remain in memory until iOS decides to remove it. This means that when you enter the app again it will be in the same state you left it. You can see if the app is still in memory by doubletapping the home button.
When your app becomes active the method applicationDidBecomeActive: in your UIApplicationDelegate will be called. You can implement that method to set the state you want your app to be in when it is restored.
I would not recommend explicitly killing the app when it is suspended. That forces the app to be reloaded each time it is started which will degrade performance.
For more information see Apple's documentation on app states.
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 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.
Is it possible to logout when the iPhone Home button is pressed?
In the current iPhone API, it is impossible to "hijack" any of the hardware presses. You will be notified of certain events however. If you are wishing to call some function (logout) when the user exits the app by pressing the home button, you can implement the
- (void)applicationWillTerminate:(UIApplication *)application {
....
}
method in your Application Delegate. This method is called when the app is about to terminate through a phone-call, manual exit, or any other reason. You should be advised, however, that anything here better be very short execution and non-essential, as Apple does not guarantee that it will run through the whole method before terminating the application
For iOS 4.0 + however you will have to implement logout in this method as well
- (void)applicationDidEnterBackground:(UIApplication *)application