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IOS app crashes when starting AR
18 CommentsSorted by Oldest First
I've implemented the Wikitude SDK in my app in order to display my Wikitude Studio content inside my app. Everything works fine except for a thing, if I start the AR class then I go back to the home screen and finally I restart the AR the app crashes.
The crash occurs when calling: self.architectView = ;
Does anyone know why does it happen and how to fix it?
Thanks
Hi Lorenzo,
Can you please over further details on the crash (crash log, stack trace) so we know the reason for the crash.
Thx and greetings
Nicola
This is the error log:
F1020 14:23:49.317847 2670616576 utilities.cc:320> Check failed: !IsGoogleLoggingInitialized() You called InitGoogleLogging() twice!
*** Check failure stack trace: ***
@ 0x1002444b8 google::LogMessage::Flush()
@ 0x1002452d8 google::LogMessageFatal::~LogMessageFatal()
@ 0x100244804 google::LogMessageFatal::~LogMessageFatal()
@ 0x100248954 google::glog_internal_namespace_::InitGoogleLoggingUtilities()
@ 0x100377714 wikitude::common_library::impl::iOSConsoleWriter::iOSConsoleWriter()
@ 0x10019eca8 -
@ 0x10019c0b4 -
@ 0x10019bfac -
@ 0x100149a38 -
@ 0x188993610 <redacted>
@ 0x1889ab6ec <redacted>
@ 0x188b3fd68 <redacted>
@ 0x188a4f430 <redacted>
@ 0x188a4f10c <redacted>
@ 0x188a4f074 <redacted>
@ 0x18898eff0 <redacted>
@ 0x188195f14 <redacted>
@ 0x188190b20 <redacted>
@ 0x1881909e0 <redacted>
@ 0x18819007c <redacted>
@ 0x18818fdd0 <redacted>
@ 0x1881894bc <redacted>
@ 0x1833f3c30 <redacted>
@ 0x1833f19d4 <redacted>
@ 0x1833f1e04 <redacted>
@ 0x183320dc0 CFRunLoopRunSpecific
@ 0x18e474088 GSEventRunModal
@ 0x1889faf44 UIApplicationMain
@ 0x100142000 main
@ 0x19885e8b8 <redacted>
Ok I got it working, the dealloc wasn't being called because I was referring to 'self' inside a block with a strong reference. What I did was create a weak self with __unsafe_unretained AugmentedRealityViewController *weakSelf = self;
and then inside the various blocks I used weakSelf instead of self, like this:
;
;
Now it works fine
You should update the docs because I took the code from there and with the sdk 5.0 I got this error that is the same error these guys are facing
Hi Lorenzo,
I Have the same problem using the Xamarin plugin. Do you have any solution for this?
Regards
I'm sorry but I never used Xamarin and I have no idea how the code works.. sorry
Hi Pedro,
Lorenzo gave the correct answer to the problem. When using the +addObserverForName method from the NSNotificationCenter, you need to make sure to not retain self inside the block. The solution is to create a weak representation of self which you can make with __unsafe_unretained or __weak. This breaks the dependency cycle and the Wikitude SDK can get deallocated.
Best regards
Andreas
Hello Andreas,
I tried this code on Xamarin, but it doesnt work:
Only work the first time, and the Controller is a Weak Reference like you say
This code works good with xamarin plugin 4.2.1, but fails on 5.0.0, dont know why ...
UIStoryboard story = UIStoryboard.FromName ("MainStoryboard", null);
var view = story.InstantiateViewController ("ViewController") as WikitudeViewController;
var weakThis = new WeakReference<WikitudeViewController> (view);
weakThis.TryGetTarget (out view);
var nav = new UINavigationController (view);
UIApplication.SharedApplication.Windows .RootViewController = nav;
UIApplication.SharedApplication.Windows .MakeKeyAndVisible ();
One more thing ... on xamarin there is no way for do
;
you can only do:
architectView.Start or architectView.Stop
In Xamarin i have tryed everything with WeakReferences but without success.
Finaly i set architectView.RemoveFromSuperview(); in the ViewWillDisappear (bool animated) and the Error:
Check failed: !IsGoogleLoggingInitialized() You called InitGoogleLogging() twice! is gone because all references are probably unset.
Hi,
Does this info help:
Please note that the Wikitude iOS SDKs are now more strict when it comes to memory handling. In case an application creates multiple instances of the SDK, the hosting application needs to make sure that the previously created instance is destroyed properly before the new one is created. Otherwise the application will crash with an stack trace like this mentioning InitGoogleLogging() twice:
Check failed: !IsGoogleLoggingInitialized() You called InitGoogleLogging() twice!
*** Check failure stack trace: ***
@ 0x1002444b8 google::LogMessage::Flush()
@ 0x1002452d8 google::LogMessageFatal::~LogMessageFatal()
@ 0x100244804 google::LogMessageFatal::~LogMessageFatal()
@ 0x100248954 google::glog_internal_namespace_::InitGoogleLoggingUtilities()
@ 0x100377714 wikitude::common_library::impl::iOSConsoleWriter::iOSConsoleWriter()
@ 0x10019eca8 -
@ 0x10019c0b4 -
@ 0x10019bfac -
@ 0x100149a38 -
@ 0x188993610 <redacted>
@ 0x1889ab6ec <redacted>
@ 0x188b3fd68 <redacted>
@ 0x188a4f430 <redacted>
@ 0x188a4f10c <redacted>
@ 0x188a4f074 <redacted>
@ 0x18898eff0 <redacted>
@ 0x188195f14 <redacted>
@ 0x188190b20 <redacted>
@ 0x1881909e0 <redacted>
@ 0x18819007c <redacted>
@ 0x18818fdd0 <redacted>
@ 0x1881894bc <redacted>
@ 0x1833f3c30 <redacted>
@ 0x1833f19d4 <redacted>
@ 0x1833f1e04 <redacted>
@ 0x183320dc0 CFRunLoopRunSpecific
@ 0x18e474088 GSEventRunModal
@ 0x1889faf44 UIApplicationMain
@ 0x100142000 main
@ 0x19885e8b8 <redacted>
The reason oftentimes is a retain cycle because the WTArchitectView or WTWikitudeNativeSDK object is strongly referenced in a block. Simply create a weak pointer to your Wikitude SDK object and use this weak pointer inside the block.
Greetings
Nicola
As i wrote before, the Error ist gone by explicitly calling architectView.RemoveFromSuperview() but i have wasted much time with building around the error/bug with a weak reference (seen before in the hint from Andreas Schacherbauer in the technical note).
Hi Frank.
Your solution does not work for me. When i get back and re-open the ViewController then get the error ... it's frustrating
Regards
Hi Pedro,
i checked my solution again and noticed that there is another important step to do.
Here is my working code from the ViewController:
public override void ViewWillDisappear (bool animated) {
base.ViewWillDisappear (animated);
if (_architectView != null) {
_architectView.Stop ();
_architectView.RemoveFromSuperview ();
}
this.Dispose (true);
}
protected override void Dispose(bool disposing) {
base.Dispose(disposing);
if (_architectView != null) {
_architectView.Dispose();
_architectView = null;
}
}
So not only the RemoveFromSuperview is important, also the overridden Dispose method is important too.
I hope it will work for you.
Lorenzo