How could I view iphone logging (eg NSLog) after app restart?
I'm interested in the answer both for using the (a) simulator and (b) an IOS device.
Background - In this case I have some issues no doubt in my code with how the application is supposed to launch, get previous state, and goto the controller/view it was at prior to it being terminated. Hence I want to see the logging as it starts up.
For seeing device logs, you can use Organizer tool available in XCode(your device should be connected with system).
For simulator you will have to re-run application from XCode.
Thanks,
Related
I've answered two different questions now, both explaining how VOIP apps don't start on start-up, yet people seem to think they do.
I'm not 100% sure myself, someone linked me to a part of the apple docs, which doesn't really mention anything about auto-starting of apps.
I was originally going on prior knowledge and this answer, but after another person saying that they do, I'm really not sure.
As far as I'm aware, apps only react to push notifications, and can't be launched into the background when a device is turned on.
Can we please clarify whether it is possible to auto-start an app or not?
Take a look at the UIBackgroundModes section in this document - it seems to state that adding the voip key will autostart an app on boot.
Edit: a sample app seems to confirm this behavior.
I confirm that setting VOIP mode works. However, I've found that the app won't restart after power up unless it was running when the device was powered off. Furthermore, the app won't actually restart on the recently powered up device until the device is unlocked after power up.
OK, I don't know if this classifies as an answer but I feel obligated to say. I am developing an app that both tracks significant location changes and provides VoIP features. The app has voip key in Required background modes. I tried some cases which I would like to share the results:
App is in Debug mode - Turned off while app was running (active or background) - iOS 7.1.1 (11D201) and iPhone 4 (product name: iPhone3,2):
When booted, app is running in background, as well as other apps that were running before. I do not think this is related to VoIP in any way.
App is in Debug mode - Turned off while app was terminated - iOS 7.1.1 (11D201) and iPhone 4 (product name: iPhone3,2):
When booted, the app is not running, there are no logs in configuration utility, server says the user is not registered I cannot call it from other devices; and yet the other apps that are not related to voip or location tracking but were open before turning off are at least loaded in memory. Meaning, the voip key did not work.
I have continued the test with the same app but this time downloaded it from app store. The results are the same. Changed the device and os to iPhone 3G (product name: iPhone2,1) and iOS 6.1.6 (10B500). Nothing changed both in debug and release modes.
I have told my boss that Apple provides this behavior and it can be done. Then I had second thoughts and tried, now I am desperately trying to find another way. Going to send my regards to Apple about this.
You can not launch an application without user interaction. The user has to click on the app icon, on push notifications, on a custom link. May be there are other ways I am not aware of, but even if they exist, they require user interaction to intentionally launch the app.
Edit
It turns out, as Tim mentioned, there might be an exception for VOIP apps.
I have been developing VoIP apps and I can confirm that VoIP app will autostart when iPhone reboots as long as user doesn't kill it before reboot. When iOS autostart voip app only application:didFinishLaunchingWithOptions: will be run, i.e. applicationDidBecomeActive: won't be run.
I used to doubt whether iOS will automatically restart the voip app when it crashes. After investigating I find iOS does automatically restart the voip app but if it keeps crashing iOS will then try servals time before it finally gives up.
If you check iPhone console output from xcode, you can see logs like these after the first crash
..
Service exited due to signal: Abort trap: xxx
Unable to get short BSD proc info for xxxx: No such process
Application 'UIKitApplication:xxxxx]' crashed.
...
Significant location change or region monitoring also causes an app to launch on boot as long as its turned on and left on. No UIBackgroundModes key is necessary for this.
I have developed an application on iPhone.
If i run it from XCode, no problem : XCode installs the app on the device, then the app is running, OK.
But then, I unplug the device from Mac, and i run the app : crash happens, OK.
I would like to know if there is a way to attach XCode as debugger when I run an app from the device, and not from XCode. Such like Windbg and dump of application crashed.
If you re-attach your device to XCode, you can access the crash log.
Go to the Organizer, select Devices, select your device, and then under your device name, you will see "Device Logs". You will be able to select and examine any of them in the next window to the right.
You will also be able to see the Console.
These should help in determining what caused the crash.
I think this is mostly due to memory issue. Check in instruments that your application consumes more memory. If so try to reduce memory conception by releasing unnecessary view controllers and mostly UIImageViews
This is my first try in moving my app to a device. I was able to launch the app by clicking on the start button on XCode to launch it on my iPhone. I stopped the app and see if I want to try whether I am able to run it without being plugged. I can still see the app icon on my iPhone but when I launch it.. it immediately closes. What am I doing wrong?
I fixed the error, it was a stupid %# where I need %f.
First delete your application from the device and run again your application from the XCode on the device and run it thoroughly while the device is connected and then try to run the application. It should then work.
It is not related to provisioning. Environment is different when the program is being debugged. Plug the iPhone back to computer and check the crash log in XCode > Organizer > Device > Device Log.
I recently installed iOS 4.2 for my iPod after then my application started to crash.
The scenario is: I launch my application wait until it's up and running then hit the iPod home button then launch my application again, my application starts again for seconds then crashes.
my application is a job search engine, so in all of its navigation pages it's communicating with internet server.
I think the problem has to do with applicationDidEnterBackground, applicationWillEnterForeground, or applicationDidBecomeActive methods. I do not have an code in these methods and I do not know if I need to, to prevent the crash.
I do not understand what happens after I hit the home button and my application goes to the background:
will it still be running in the background (because of the multithreading thing in iOS4.2).
Sometimes when I relaunch my application it goes to last page I left in before hitting the home button and sometime it starts from the home page.
I do not understand what's going on, I just want it every time it starts to start in the home page.
I was just about to submit my application to the Apple Store just before I updated to iOS4.2 and the crash starts to happen. I'd really appreciate if someone can help me with this issue that I'm not even able/or know how to debug.
Thanks a lot in advance.
Regards,
You can set the Info.plist key ApplicationDoesNotRunOnBackground to make sure the app is completely terminated.
Xcode / Organizer will show your device crash logs.
Xcode -> COMMAND+CONTROL+O -> Device Logs or you (making sure the device is connected) can select the iPod from the list of devices, then choose Device Logs.
You don't need to have any code in the applicationDidEnterBackground, applicationWillEnterForeground, or applicationDidBecomeActive delegates, so that's not making your app crash.
I would definitely check out some of those logs in Organizer. Maybe post some of them here, or pastie.org
When I run my app with simulator every thing is ok.also when i run it on device (ipod touch 3G) for the first time,i have no problem but if i close my app and run it again,it hangs(no button working & just i can uninstall it) and if i try to minimize it ios seems out of action(every thing is being black)
how can i solve this problem ?
Run your application in the simulator with the profiling tools, making sure you check for allocations / releases and if there are any network resources left open.
You haven't said anything about what your app does to give any more help than that, but the development tools will tell you what is going on.
Also when you connect to the iPod, check the crash reports to see what happened
have u release any object in appWillTerminate. may be u trying to release object that is already released before the application quit. or u can see the application quit status in nslog if status is not 0 means application is not quitting properly.