When the app that I'm developing is launched, the user returns at the view that was open the last time before close. This seems to be normal behaviour. Can I turn this off to make sure that the user always starts with a login view ?
thanks for your advice
Frank
You are probably running on iOS >= 4.0. That is the default behavior. To disable is set UIApplicationExitsOnSuspend to true on your Info.plist.
As Felz pointed out, you can disable this easily. I would recommend though leaving it on and developing another solution. Users generally appreciate if the app reopens where they left it. Maybe they want to quickly look up something, maybe they simply get a phone call - when they come back, they don't want to reenter login information.
If your app displays secret information or something else that you don't want to be easily accessible, you could still implement a timer: When the app has been running in the background for some time, e.g. 5 minutes, and is reopened, you could display your login screen again.
Related
I have a problem about detecting sleep date and saving it. The thing is I want to run a counter, when you open the app it always count how much time passed and based on that calculates something. The thing is I want to stop counting if the computer is going to sleep. Is there any way to do this in background if the actual desktop app is not running?
I have tried NSWorkspace.willSleepNotification, but its not called if the app is not running, I also tried to do this in a menu bar app if its only an Agent its also not called, maybe its not possible to do.
You need to improve your question by showing us some code, so that we can help you with what you are doing wrong. I have a background app without a menu bar and I do get these notifications. And yes, you will ONLY get this notification if your app is running. What I usually do I create a background-only app to register those notifications, which I will pass to the main app, via a file or an Apple Event.
My app has to run for a long time (also) in the background, due to Location Services.
When a certain condition is met the app has to move to the foreground.
I was able to run my app in the background and bring it to the front manually.
Reading up on this issue I got confused on how to move my app to the foreground by code.
It has to be in an if statement but what to do from here?
No do not think this is possible. You will be able to spawn a UILocalNotification to show application state to the user, but it is my understanding that iOS prevents you from making your app take focus.
you can't do that without user interaction. You can present a UILocalNotification
-- you can't even be sure iOS leaves it running though!
on a jailbroken phone I guess it is possible
This is clearly not possible, as it would be a mess if any app could just take over control at any point in time. As mentioned, you have to post a notification, and then it is up to the user if he or she wants to launch the app. If you notification states a good reason why they should launch your app, they might very well do it :-) And remember, don't mix up the user's needs with your/your app's needs.
We don't want the user enter our app if the app is out-dated.
Is that is possible to quit a iOS app when we do some date check BEFORE the app launch?
Or it is possible to quit the application after the main view is loaded?
Before the app launches: no. The launch animation is already in progress when the OS calls main.
After some time (1-2 sec): yes. You can use one of
[[UIApplication sharedApplication] terminateWithSuccess];
exit(0);
abort();
assert(0);
pthread_kill(pthread_self());
so many ways, but neither will go through AppStpre - you're not supposed to close your app programmatically. You're supposed to notify the user via an UIAlertView about the outdated app and disable interaction with the app.
According to Apple you cannot exit(quit) your application through code. i.e if you use exit(0). Your application will be rejected for that. Although you can use exit(1) and delay the exit time of your application. Or you may like to use local notification which is quite handy.
Don’t Quit Programmatically
Never quit an iOS application programmatically because people tend to
interpret this as a crash. However, if external circumstances prevent
your application from functioning as intended, you need to tell your
users about the situation and explain what they can do about it.
Depending on how severe the application malfunction is, you have two
choices.
Display an attractive screen that describes the problem and suggests a
correction. A screen provides feedback that reassures users that
there’s nothing wrong with your application. It puts users in control,
letting them decide whether they want to take corrective action and
continue using your application or press the Home button and open a
different application
If only some of your application's features are not working, display
either a screen or an alert when people activate the feature. Display
the alert only when people try to access the feature that isn’t
functioning.
Source
I would like to close an iPad application as a result of clicking on a UIButton. However, I have not seen how to do this in the Apple documentation.
What call needs to be made to close an app?
Thanks.
You can call exit(0) to terminate the app. But Apple don't like this as this gives the user a feeling of sudden crash. If you still want to have an exit function (with a potential risk of rejection) then you should also send your app delegate the applicationWillTerminate message (if you have anything important there) before performing the exit.
It says:
Don’t Quit Programmatically
Never quit an iOS app programmatically because people tend to
interpret this as a crash. However, if external circumstances prevent
your app from functioning as intended, you need to tell your users
about the situation and explain what they can do about it. Depending
on how severe the app malfunction is, you have two choices.
Display an attractive screen that describes the problem and suggests a
correction. A screen provides feedback that reassures users that
there’s nothing wrong with your app. It puts users in control, letting
them decide whether they want to take corrective action and continue
using your app or press the Home button and open a different app
If only some of your app's features are unavailable, display either a
screen or an alert when people use the feature. Display the alert only
when people try to access the feature that isn’t functioning.
The only way for a user to exit an application is by pressing the Home button. You can't do it in your app, at least not in a way that Apple would accept.
You can try to use command:
exit(0);
I am fairly new to iphone app development. I am creating an app that has multiple views. Initially it starts with a view for authentication and then load views according to user interaction. When I build and run the app - the first time it shows the "Default.png" screen and then shows the first view where I do my authentication process (typing in userid,password and do a web service) and then after the credentials are verified it takes me to the next view. When I close the app at this state in the simulator and reopen it again, I am seeing the same state in which I closed my app. But here is what I want. When I relaunch the app I should be able to show the "DEfault.png" and screen and then show my initial authentication view. Can you please help me out on this ? Thanks
It sounds like the problem you are trying to solve is that your authenticated session may time out while the app is suspended and you need to log in again.
Although the proposed solution (setting UIApplicationExistsOnSuspend to true) would work I think you should consider a different approach.
Apple recommends that you do everything you can to make it look like the phone supports multitasking. That is why, by default, your app will suspend and resume instead of exit and relaunch. In your case, though, you may need to re-login to resume the session. I offer you a couple of alternate solutions:
Cache the credentials (ie username and password) and silently use them to resume the session when needed. If the back-end supports this.
Detect when the session has become stale and bring in a view to inform the user that the session has expired and ask them to log in again. This would also address the issue if the user keeps the app active past the timeout of the session.
Both of these approaches should improve perceived app performance and integrate better into the Apple usability guidelines.
That's because iOS 4 apps are supposed to support multitasking. You can change the app so it doesn't: In Info.plist, set UIApplicationExitsOnSuspend to true (i.e. <key> UIApplicationExitsOnSuspend</key><true/>) — make sure it's a boolean and not a string. Note that this will probably make startup slower, since the app has to be launched again.
The other way is to handle applicationDidEnterBackground: in your app delegate and do two things:
Reset your view hierarchy (you can do this on next launch, but doing it earlier might help to free more memory)
Show "Default.png" in a full-screen view — iOS takes a screenshot of your app after it's hidden which it uses to animate the app back in.