When my app is running in foreground, If user clicks on home button i want to show some alert like
Do u want to exit the app with Yes/No buttons. Is there any delegate methods called when home button is clicked…
Thank you….
There is no way to do this on iOS. I think you want a similar behavior to Android back button.
Think of iOS home button as Android home button, which doesn't let you prompt user either.
You can not stop the app to go to background, even if you show the alert message, it will go to the background anyways when you hit the home button and you won't see the alert message either.
There is no delegate method that would trigger when the app is going to the background, but there is a delegate method that will trigger when your app has totally gone to background.
Just to show you visually-
In the AppDelegate implementation file(.m), I added an alert message at the end of applicationDidEnterBackground method and put a break point just to check if it is entering that block as I expected. See the result--
You can use these methods in AppDelegate.m
- (void)applicationDidEnterBackground:(UIApplication *)application {
// 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.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
Related
I have a PrayerButton in my drawer menu, On tapping it goes to
PrayerViewController, and in PrayerViewController
i have 5 Prayer Timings where i created a UI local notification method and fired those timings in firedate and sound too. now my query is.
where should i call my notification method.
“All i want is my local notification method should call when my app is in Background, foreground and it should continuously running like a service, so that whenever those 5 Prayer time will come on firedate then it should alert me by UI Local Notification banner (when in foreground) and if app is in background it should notify me".
i am a beginner in Stackoverflow might be my way of asking question will not be right but i tried asking Question.
sorry for the mistakes
and welcome to any reply
thanks in advance..
Use these app delegate methods
func applicationDidEnterBackground(application: UIApplication) {
// 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.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
func applicationWillEnterForeground(application: UIApplication) {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
I am asking if I can repeat a method in Xcode after home button pressed. Let's say every 30 minutes.
I have no idea to do it if it is possible.
I think your question is related to background execution by saying after home button pressed. First you need to address how to call the function in the background.
Here is what I recommend for you to follow:
First:
I recommend you to take a look at the apple official document.
https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html
Second:
There is a good tutorial:
http://pinkstone.co.uk/how-to-execute-a-method-on-a-background-thread-in-ios/
Third:
Here is what you are asking:
http://chrisrisner.com/31-Days-of-iOS--Day-23%E2%80%93Using-Background-Threads
Fourth:
If you want to explore the advanced material:
http://mobiforge.com/design-development/using-background-fetch-ios
use NSTimer
[NSTimer scheduledTimerWithTimeInterval:"your time"
target:self
selector:#selector(your method:)
userInfo:nil
repeats:YES];
There are Methods (like "viewDidLoad") that gets called for these cases. Here are some:
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
// 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.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
you can place the NSTimer in one of these and anything else you want to do when the home button is pressed. Hope this helps.
Source: Detect when home button is pressed iOS
I have recently been having some trouble with iOS 7 and unlocking. I am trying to get an UIAlertView to display every time a user unlocks his/her device.
I have gotten the same thing to work with respringing. I am using iOSOpenDev with the logos template. Does anyone know how to achieve an Alert right after unlocking with iOS 7's SBLockscreenViewController, or with something else?
Check out these methods from SBLockScreenViewController:
-(void) prepareForUIUnlock;
-(void) finishUIUnlockFromSource:(int)source;
Both should work fine.
Every time when your application becomes active the following action will be called:
- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
I have an animation based timer app that does not reset when I exit the app. I need to click the home button, then quit the app and re-launch it to get the timer to reset. How do I tell the app to reset when the home button is pushed?
What you are looking for is (source):
- (void)applicationDidBecomeActive:(UIApplication *)application
This method is called to let your application know that it moved from the inactive to active state. This can occur because your application was launched by the user or the system. Applications can also return to the active state if the user chooses to ignore an interruption (such as an incoming phone call or SMS message) that sent the application temporarily to the inactive state.
You should use this method to restart any tasks that were paused (or not yet started) while the application was inactive. For example, you could use it to restart timers or throttle up OpenGL ES frame rates. If your application was previously in the background, you could also use it to refresh your application’s user interface.
OLD ANSWER:
In your UIApplicationDelegate, there is a delegate method:
[– applicationDidEnterBackground:][2]
which is called when you app enter background. You could stop the timer there.
If you also want that the timer is stopped in the face of other interruptions, like an incoming call, you could use:
applicationWillResignActive
Which is the proper delegate to implement when an application is waking up from being in the background and you want it to prep it to be active?
applicationWillEnterForeground vs applicationDidBecomeActive -- What's the difference?
Which is the proper delegate to implement for when an application is going to sleep and you want to prep it to cleanup and save data?
applicationWillResignActive vs. applicationDidEnterBackground -- What's the difference?
Also, I've noticed that applicationWillResignActive gets called when an incoming SMS or call comes in but the user chooses to click Ok and continue. I don't want my app to take any action in these cases. I just want it to keep running without any intermediate cleanup since the user didn't exit the app. So, I would think it makes more sense to do cleanup work just in applicationDidEnterBackground.
I would appreciate your input on best practices to follow on choosing which delegates to implement for waking up and going to sleep as well as considering events like being interrupted by SMS/calls.
Thanks
When waking up i.e. relaunching an app (either through springboard, app switching or URL) applicationWillEnterForeground: is called. It is only executed once when the app becomes ready for use, after being put into the background, while applicationDidBecomeActive: may be called multiple times after launch. This makes applicationWillEnterForeground: ideal for setup that needs to occur just once after relaunch.
applicationWillEnterForeground: is called:
when app is relaunched
before applicationDidBecomeActive:
applicationDidBecomeActive: is called:
when app is first launched after application:didFinishLaunchingWithOptions:
after applicationWillEnterForeground: if there's no URL to handle.
after application:handleOpenURL: is called.
after applicationWillResignActive: if user ignores interruption like a phone call or SMS.
applicationWillResignActive: is called:
when there is an interruption like a phone call.
if user takes call applicationDidEnterBackground: is called.
if user ignores call applicationDidBecomeActive: is called.
when the home button is pressed or user switches apps.
docs say you should
pause ongoing tasks
disable timers
pause a game
reduce OpenGL frame rates
applicationDidEnterBackground: is called:
after applicationWillResignActive:
docs say you should:
release shared resources
save user data
invalidate timers
save app state so you can restore it if app is terminated.
disable UI updates
you have 5 seconds to do what you need to and return the method
if you don't return within ~5 seconds the app is terminated.
you can ask for more time with beginBackgroundTaskWithExpirationHandler:
The official documentation.
Managing Your App's Life Cycle is helpful to your questions. For quick concept, you can see Figures in that document.
You can also read the comment from the code generated by the XCode Wizard. Listed as follows:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
/*
Sent when the application is about to move from active to inactive state.
This can occur for certain types of temporary interruptions (such as an
incoming phone call or SMS message) or when the user quits the application
and it begins the transition to the background state.
Use this method to pause ongoing tasks, disable timers, and throttle down
OpenGL ES frame rates. Games should use this method to pause the game.
*/
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
/*
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.
If your application supports background execution, this method is called
instead of applicationWillTerminate: when the user quits.
*/
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
/*
Called as part of the transition from the background to the active state;
here you can undo many of the changes made on entering the background.
*/
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
/*
Restart any tasks that were paused (or not yet started) while the
application was inactive. If the application was previously in the
background, optionally refresh the user interface.
*/
}
- (void)applicationWillTerminate:(UIApplication *)application
{
/*
Called when the application is about to terminate.
Save data if appropriate.
See also applicationDidEnterBackground:.
*/
}
For more detailed explanations, please refer to official document for UIApplicationDelegate
I was still a bit confused with Dano's answer so I did a little test to get the flow of events in certain scenarios for my reference, but it might be useful to you too. This is for apps that DO NOT use UIApplicationExitsOnSuspend in their info.plist. This was conducted on an iOS 8 simulator + confirmed with iOS 7 device. Please excuse Xamarin's event handler names. They are very similar.
Initial and all subsequent launches from a not-running state:
FinishedLaunching
OnActivated
Interruption (phone call, top slide-down, bottom slide-up):
Home button double-press listing inactive apps, then reselecting our app:
OnResignActivation
OnActivated
Home button double-press listing inactive apps, selecting another app, then relaunching our app:
Home button single press, then relaunch:
Lock (on/off button), then unlock:
OnResignActivation
DidEnterBackground
WillEnterForeground
OnActivated
Home button double-press, and terminate our app: (subsequent relaunch is first case)
OnResignActivation
DidEnterBackground
DidEnterBackground (iOS 7 only?)
Yes, DidEnterBackground is called twice on iOS7 device. Both times UIApplication state is Background. However, iOS 8 simulator does not. This needs testing on iOS 8 device. I will update my answer when I get my hand on it, or someone else could confirm.
applicationWillEnterForeground is called:
when app is relaunched(comes from background to foreground)
This method is not invoked when app starts for the first time i.e when applicationDidFinishLaunch is called but only when comes from background
applicationDidBecomeActive
applicationDidBecomeActive is called
when app is first launched after didFinishLaunching
after applicationWillEnterForeground if there’s no URL to handle.
after application:handleOpenURL: is called.
after applicationWillResignActive if user ignores interruption like a phone call or SMS.
after disappearing of alertView anywhere from the application
applicationWillResignActive is called when system is asking for permissions. (in iOS 10). Just in case someone hit into the same trouble as me...
In iOS 8+ there is a subtle but important difference for taking phone call.
In iOS 7 if user takes phone call both applicationWillResignActive: and applicationDidEnterBackground: are called. But in iOS 8+ only applicationWillResignActive: is called.
For iOS 13+ the following methods will be executed:
- (void)sceneWillEnterForeground:(UIScene *)scene
- (void)sceneDidBecomeActive:(UIScene *)scene