I want to cancelAllLocalNotifications and setApplicationIconBadgeNumber to 0 when my application is terminated (either by the OS or by double tapping the home button and killing the app). I simply added these two calls to my primary app delegate code:
-(void)applicationWillTerminate:(UIApplication *)application
{
[application cancelAllLocalNotifications];
[application setApplicationIconBadgeNumber:0];
}
Existing notifications are still running and the badge number remains set?
applicationWillTerminate: is not called by the OS when it kills your app. The OS just kills the process without notifying your app about it. There is no documented way to execute code at this moment.
You should use applicationWillResignActive: instead.
Starting with iOS 4.0 applicationWillTerminate is not called for applications when they are killed in the background. Apps are put in the background when you hit the home button now or otherwise switch apps.
Related
Is there any Swift command to actually set the Auto-Lock to Never or a specific time period? I want to create a simple app that only has two buttons: one is to set the Auto-Lock to Never and the other one is to set it back to iOS default (1 min).
So when a user open this app and tap the Never button, s/he can open other apps but the iPhone or iPad will never auto lock while running the other apps. If s/he is done with other apps, s/he can open this app again and tap the Default button to set the Auto-Lock back to 1 min.
I understand this can be done from the Settings but I am just curious how I can do it from the backend using Swift.
I am new to Swift, btw.
Thanks much!
So when a user open this app and tap the Never button, s/he can open other apps but the iPhone or iPad will never auto lock while running the other apps
You can't do that. You are sandboxed. You cannot affect what happens to the user while running some other app.
When app is open, try to disable the idleTimer in viewDidLoad
UIApplication.shared.isIdleTimerDisabled = true
When app is closed to open other apps, try to -enable again idleTimer when yourViewController disappears, so put this in viewDidDisappear
UIApplication.shared.isIdleTimerDisabled = true
You need to make use of this API call to set the idle timer disable and enable.
This is in objective-C. Just convert it to swift. The API is available in UIApplication.h
-(void) onApplicationDidActivate:(NSNotification*) notification
{
[[UIApplication sharedApplication] setIdleTimerDisabled:NO];
}
-(void) onApplicationWillDeactivate
{
[[UIApplication sharedApplication] setIdleTimerDisabled:NO];
}
When the application is on and when we leave it to idle, the screen gets lock. When the user unlocks it (slides), I need to relaunch the application.
For that i used the following code in the applicationDidFinishLaunching method.
[[UIApplication sharedApplication] setIdleTimerDisabled: YES];
Still the application doesn't relaunch after the screen is unlocked. Help, what should i do to make this work ?
You do not have to do anything for that. If an application is open before locking the iphone, it will be open, if you unlock it again.
setIdleTimerDisabled just ensures, that the device won't go to sleep on its own, while your application is running. In most cases you shouldn't use this application-wide.
we have an app that has a specific purpose where an exit is required. After the exit a process needs to run in the background for a certain amount of time or until finished. We just need to know how to programmatically force the app to enter the background where processes can continue running. Any help on this would be great! Thanks in advance!
UPDATE: We have confirmed that there does not seem to be a programmatic way to force the app to quit / enter background and continue running background tasks. You can force the the app to exit using exit(0); but this kills the app all together. However, the bulk of this question was concerning running tasks in the background. We have found a solution that allows our app to begin processing data and handling tasks that a user has setup to be processed. Here is the code required. This needs to be added to the app delegate and multitasking is required on the device / IOS.
- (void)applicationDidEnterBackground:(UIApplication *)app{
// Check that IOS supports multitasking
if ([[UIDevice currentDevice] respondsToSelector:#selector(isMultitaskingSupported)]){
// Check that the device supports multitasking
if ([[UIDevice currentDevice] isMultitaskingSupported]) {
// Custom setting to allow users the freedom to enable or disable background tasks
BOOL enabled = [[NSUserDefaults standardUserDefaults] boolForKey:#"backgroundTasksEnabled_key"];
if ( enabled ){
//Get the shared application instance
backGroundApp = [UIApplication sharedApplication];
background_task = [backGroundApp beginBackgroundTaskWithExpirationHandler: ^ {
[backGroundApp endBackgroundTask: background_task];
background_task = UIBackgroundTaskInvalid;
}];
// Run in background
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSLog(#"\n\nProcess background tasks!\n\n");
// Do your work here
});
}
}
}
}
You can force an iOS app into the background by sending a registered URL to another app to handle, such as a web site URL to Safari.
[[UIApplication sharedApplication] openURL:[NSURL URLWithString: myWebsiteURL ]];
Many many apps that call Safari to handle URLs are approved by Apple.
To get any time in the background, an app has to be appropriately configured using one of the allowed background modes (audio, location or VOIP); or the app can request a few minutes of extra time in the background before being suspended by calling the beginBackgroundTaskWithExpirationHandler method
You can't have a process running (doing work) in the background in iOS, you get a few seconds when the app quits to do any clean up and that's it!
You cannot force an application into the background, I'm fairly sure that Apple's guidelines prohibit you from doing that. What could your app possibly be doing that it can only do in the background and not in the foreground?
Hi I have read several questions on SO about applicationWillTerminate getting called and not getting called.
I wanted to summarize what I understood as there are several posts that speak differently.
For IOS (without multitasking) it is called always when home button is pressed.
For IOS 4 and above
a. it is not called when pressing home button (as the app moves to background)
b. it is called when closing the app from the multi tasking dock and if the app has a sudden terminate flag in info.plist disabled else it is not called. ( I set the "Application should get App Died events" and even then on closing the app from the multitasking dock the terminate function did not get called)
Based on that I had a couple of questions
Is it a good practise to set the Application should get App Died events flag? ( I set the "Application should get App Died events" and even then on closing the app from the multitasking dock the terminate function did not get called)
or
Is registering for "UIApplicationWillTerminateNotification" a better thing to do than the info.plist setting?
Basically I need to do some work only when the app terminates and NOT when it moves to background.
or
EDIT (1):
When the app is terminated the following is sent to the APP. How do I catch it?
Program received signal: “SIGKILL”.
EDIT (2):
Please note : It is not getting called in IOS 4 and above when removing from the multitasking dock. You might think it is. But in my case it is not.
I am asking if anyone knows why? Is there something else I am missing.
Also Note I set the "Application should get App Died events" and even then it is not getting called.
EDIT (3):
The answer for the following question also did not work.
applicationWillTerminate does not get invoked
Anybody facing the similar issue as me?
In short, unless you have UIApplicationExitsOnSuspend in your Info.plist set to YES, in iOS4 and above there is no guarantee that applicationWillTerminate: will ever get called.
As the documentation says:
For applications that support background execution, this method is
generally not called when the user quits the application because the
application simply moves to the background in that case. However, this
method may be called in situations where the application is running in
the background (not suspended) and the system needs to terminate it
for some reason
(Emphasis mine.)
If you need to do something before the app exits you need to do it in applicationDidEnterBackground:. There is no way to catch SIGKILL.
I see -applicationWillTerminate: getting called with the following test. In a new project (I used the 'Single View Application' template), add the following to the AppDelegate:
- (void)applicationDidEnterBackground:(UIApplication *)application
{
NSLog(#"%s", __PRETTY_FUNCTION__);
__block UIBackgroundTaskIdentifier identifier = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
if (identifier != UIBackgroundTaskInvalid) {
[[UIApplication sharedApplication] endBackgroundTask:identifier];
identifier = UIBackgroundTaskInvalid;
}
}];
dispatch_async(dispatch_get_main_queue(), ^{
for (int i=0; i < 20; i++) {
NSLog(#"%d", i);
sleep(1);
}
if (identifier != UIBackgroundTaskInvalid) {
[[UIApplication sharedApplication] endBackgroundTask:identifier];
identifier = UIBackgroundTaskInvalid;
}
});
}
- (void)applicationWillTerminate:(UIApplication *)application
{
NSLog(#"%s", __PRETTY_FUNCTION__);
}
This example will start a background task when the app enters the background. The task is just a 20s delay (with logging once a second) that keeps the app running in the background (note the difference between running in the background and suspended) long enough to allow it to be killed from the app switcher.
So, to test it, run the app, hit the home button to send the app to the background, then before the 20s delay is up, remove the app from the app switcher. After the end of the 20s, -applicationWillTerminate: is called. You can watch the console in Xcode to verify that this is the case.
I tried this in the iOS Simulator for iOS 5.1 and 6.1 (both iPhone) and saw it happen in both cases. I also tested on iPhone 4S running iOS 6.1.2 and saw the same behavior.
As I know, there are 3 situations that your application will die.
Terminated by the end user, you can do something in -[UIApplication applicationWillEnterBackground:], in which case, -[UIApplication applicationWillTerminate:] will NOT be called.
Dropped by the system, such as memory not enough, you can do something in -[UIApplication applicationWillTerminate:], in which case, we do NOT know whether applicationWillEnterBackground: has been called;
Crashed, nothing can be done except using some kind of Crash Reporting Tool. (Edited: catching SIGKILL is impossible)
Source: http://www.cocos2d-iphone.org/forum/topic/7386
I copied my state saving code from applicationWillTerminate to applicationDidEnterBackground and also added a multitaskingEnabled boolean so that I only call state saving in applicationDidEnterBackground. BECAUSE, there is one instance on a multitasking device where applicationWillTerminate is called: If the app is in the foreground and you power off the device. In that case, both applicationDidEnterBackground and applicationWillTerminate get called.
As we know that the App has only 5 sec when -applicationWillTerminate being called. So If someone want to update the server at that point. Than use
Synchronous call.
[NSURLConnection sendSynchronousRequest:urlRequest returningResponse:nil error:&error];
Note:- -applicationWillTerminate will not call if app is being killed from suspended state. Suspended state means app is not working anything in backgroupd. One of the solution for this is to use background task.
Based on Andrew's test, I understand the docs for applicationWillTerminate(_:) to be meant as having the following clarifications:
For apps that do not support background execution or are linked against iOS 3.x or earlier, this method is always called when the user quits the app. For apps that support background execution, this method is generally not called [right away] when the user quits the app because the app simply moves to the background in that case. However, this method may be called [instead of beginBackgroundTask(expirationHandler:)] in situations where the app is running in the background (not suspended) and the system needs to terminate it for some reason.
// absolute answer applicationWillTerminate
func applicationWillTerminate(application: UIApplication) {
print("applicatoinWillTerminate")
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
step 1: command + shift + h (double click(tab))
step 2: move app top side (kill)
step 3: applicationWillTerminate Work
Why debugger didn't launch to - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions when I launch the App after killing my app process from multitasking ? "killing app process from multitasking" mean to make double click on "Home" button, after that, at the bottom of iPhone menu with active apps will be shown, and than I delete my app there. thanks...
If you launch your app from the iPhone screen (pressing its icon) after you have killed it, the debugger is not attached to it any more, hence it will not launch. You need to trigger the application from XCode again.
If the app's getting killed, regardless of from where, - (void)applicationWillTerminate:(UIApplication *)application will get called. application:didFinishLaunchingWithOptions: only gets called when the app launches, not when it quits…hence the names.