i have a subclass of UIViewController, and when it is called from another class the app just freezes - i used the Xcode debugger and figured that when I'm trying to access the class's view property the app freeze. another weird thing is that when i type in the debugger control panel: "po objectOfTheProblematicClass.view" the debugger stops responding.
the code I used was similar to this:
UIStoryboard *sb = [UIStoryboard storyboardWithName:#"Main" bundle:[NSBundle mainBundle]];
WTStickyViewController *stickyVC = [sb instantiateViewControllerWithIdentifier:#"WTStickyViewController"];
stickyVC.sticky = sticky;
// Setup view controller containment:
[self.parentViewController addChildViewController:stickyVC];
self.containerView = self.parentViewController.view;
[self.containerView addSubview:stickyVC.view];
WTStickyViewController is the subclass of UIViewController. the app freezes when it reaches
[self.containerView addSubview:stickyVC.view];
but it's because this is the first time that stickyVC.view is called.
if for example i would put somewhere in the code
UIView *viewForExample = stickyVC.view;
the app would freeze there.
the exact same app works fine when compiled on a device with iOS 8 but has this problem with iOS 9.
if anyone knows why is this happening and if there is a solution it will be great. thank you.
I was having a similar issue and it was absolutely maddening. The CPU went to around 100% in the resource monitor during debug as the app deadlocked. Printing to console or just generally accessing the view controller's view property caused this behavior. Ultimately, what 'fixed' it for me was removing it from the base localization file. I know that doesn't make sense, but I'll elaborate as best as I can.
I'm maintaining a legacy universal app that has 2 'main' storyboards called Main_iPhone and Main_iPad, which as you can probably guess are the loaded dynamically based on what device you're launching on. I noticed that only the iPhone nib view was deadlocking as described, and iPad was loading fine. The only thing I could tell as that the iPhone storyboard had localization enabled while the iPad storyboard had not. So here's the steps I took loosely to remove it from base localization (you may want to do this in a separate branch/sandbox to make sure this works before deleting project references):
Right click the problematic view and/or storyboard in question, show in finder. For me it was inside the Base.lproj folder as expected.
[Re]move the file to a different directory so Xcode can not find the link the project (file goes red in file browser). Press delete to remove the file from the project file's reference from the project itself.
Add the file back at the new location in your repository/project structure so Xcode picks it up as a new file. Ensure all of your references to the file are updated to the new location.
Verify your storyboard/xib file is not localized anymore, clean project, re-run and see if the issue is still there (see image).
You can also just update the file location using the update location button in the file properties view on the right side (see other image).
Don't know if this will fix it, but I thought I'd share what helped me in the chance that it helps others as well.
A bug report was sent to apple and hopefully it will be fixed soon - the problem is indeed with Xcode 7.
If you are encountering a similar problem, it can be solved by doing one of the following:
1) Use Xcode 6.4, at least until apple fixes this bug.
2) Rebuild the problematic view in the storyboard.
I will post the radar link once I got a chance to speak with my manager about it...
Related
I am banging my head against a brick wall. I am trying to push a view onto a UINavigationController in the usual manner:
[[self navigationController]pushViewController:vc animated:YES];
When I do this the app crashes with the following error:
__CFStringEncodeByteStream + 17
Thread 1: EXC_BAD_ACCESS (code=2,address=xxxxx)
Now, I have replaced the ViewController in question with a template provided by XCode and I do not get the error so the issue must be with my UIViewController class. Furthermore, if I replace the nib name with that of the template UIViewController class it works .i.e.
MyViewController *myVc = [[MyViewController alloc]initWithNibName:#"XCodeViewController" bundle:nil];
This leads me to think that the issue is actually with the nib and not the class itself. I have checked through all the connections and there are no errors or warnings.
Hopefully somebody can help.
Thanks
I was dealing with a very frustrating bug similar to yours, and everything was in place.
The newly created xib was added to the Bundle resources, no nil pointers or released pointer, NSZombieEnabled was set. The File's Owner was set to the correct ViewController as well
After sitting down with my senior for 30 minutes, we finally realized what was wrong -
In the newly created Xib, even after you assign the File's Owner to the ViewController there is an additional step which you need to take.
You need to have the main View's referencing Outlet set to the File's owner as well. The easiest way to do this is to Drag the "+" sign on the referencing outlet(From the Connections inspector) to the "File's Owner" in the Document Outline. After this you just need to click on "view" which pops up and you should be good.
Hope that helps you or anyone else facing the same problem
Need more info to answer, I can give few possibilities.
Check if the class name is mapped properly in your identity inspector.
And check your connections too. If your view is mapped in xib., etc.
If your running the app in OS below 6.0 & built with features such as Auto layout, it leads to crash.
There are multiple possibilities.
Hope this gives an insight.
Check if your nib is added to the application bundle. You can do that by selection you project file->Build Phases->Copy Bundle Resources.
If it is not there, add it.
I had the same issue yesterday and this was the problem.
I hope it helps.
My question is specific to iPAD, and I also aware of the basic memory management of iOS, but I am having a different problem.
As I have build an application where I have several UIViewControllers and UIViews,
I have a loginController thats gets called when I launch the App.
My MainView is a single screen with all the ViewController loaded and placed at their respective places and the app runs fine and smoothly.
Problem:
Problem comes when I logout, most of the time my App crashes by saying EXC_BAD on the
[super dealloc] line of my mainView controller.
As for now on I have added a custom function cleanUP in all my viewControllers that gets called when user logout from the app.
Is this the right approach ?
As I know that we can clean up in our didload etc. function and the dealloc gets called too.
but here i have an iPAD when my all viewControllers are just open in front of me, They will be closed or not visible when I logout from the App.
So how to approach on my crash issue and How to manage memory here in my iPAD?
The best way I know to resolve bad-access problems is to use Instruments with the Zombie tool. As you probably know, when you get a bad access issue, is because you try to access to an object that is deallocated.
Try go to Product -> Profile and choose Zombie. Hit record and reproduce your crash. then inspect the pointer to the object that produced that crash and look for the retain count.
I am trying to make a simple app from a tutorial that does not have a viewController at all. All the code is in the AppDelegate. I am on xcode 4.2 and I am getting this error:
Applications are expected to have a root view controller at the end of application launch
I'm not sure how to deal with this. There are some blogs out there with fixes but none of them are working for me and I really would like to understand what is going on here. And, how to fix it.
I do have a view that contains some buttons and labels. But I have no "ViewController". The files contained in my project are: AppDelegate.h, AppDelegate.m, and Window.xib only. There is no ViewController.h, ViewController.m
** edit **
I ended up making the app from a 'view based application' instead and just moving all the logic from the app delegate to the view controller. So, I didn't really solve the problem per se. The app works now though. Thanks for the help
It's not possible to have an iOS app that doesn't have a view controller. You can always create a trivial view controller, i.e.,
[[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds].rootViewController =
[[[UIViewController alloc] init] autorelease];
It sounds like you're looking at an old tutorial. UIWindow got a rooViewController property in iOS4. I believe it became required in iOS5 to help keep controller hierarchies and view hierarchies in sync with the addition of custom container controllers (and to fix a corner case where replacing the "root controller" of a UIWindow could stop orientation changes from propagating). There was a WWDC presentation in 2011 that explained this in some detail. I think it was Session 102, Implementing UIViewController Containment.
At then end of the day, there's no good reason not to have a root view controller. Apple wants to be able to assume it's there in their APIs going forward. If the tutorial you're looking at doesn't account for that, it's broken.
While I agree that there may be workarounds, another question to address is: why do you want an app without a view? Even if it's designed to run in the background and present no visual interface, at least make a simple view showing the application name and version, a largeish icon and perhaps a status. This kind of idle screen uses very little system resources, especially when the app is backgrounded, but improves the overall experience of the app.
If you set your deployment target to 4.3 and run on the iPhone 4.3 simulator, you won't get the warning.
To install the iOS 4.3 simulator, go to Xcode > Preferences > Downloads.
At a great number of requests from people using older iOS hardware, I'm currently refactoring and optimizing my app so it will work on iOS 3. That being said I've got a glitch with my UITabBar that I can replicate on all of the iPhone 3G units I've tested it on.
The glitch appears to have been fixed in iOS 4, but I was wondering if before that time, anyone else had this glitch as well and had figured out a (relatively elegant) workaround for it.
The problem is what you can see below; when a memory warning occurs and all of the views offscreen are released, when I bring a view controller with a tab bar back on screen, all of the UITabBarItems that are supposed to be in it are gone. As far as I can see, they're not being drawn at all; ie tapping the tab bar has no effect. After setting breakpoints and examining the UITabBar and its items in memory, they're all still there (ie not getting released), just that they're not getting redrawn when the UITabBar is re-created in the controller loadView method.
My app works similar to the official Twitter app in that I implemented my own version of UITabBarController so I could control the integration of it with a parent UINavigationController properly. I set it up as closely as possible to the original UITabBarController class though, with all of the child view controllers handling their own respective UITabBarItems and initializing them inside the class' init methods. Once the child view controllers are passed to my TabController object via an accessor method, the tabBarItems are accessed and added to the UITabBar view.
Has anyone seen this behaviour before and know of a way I can fix it? I'm hoping there's a really simple fix for this since it already works in iOS 4, so I don't want to hack it up too badly.
Thanks a lot!
After a bit of research, I think I found a solution to this. It's not the most elegant solution I was after, but it definitely works.
I'm guessing after a memory warning is triggered, something is happening to the UITabBarItem objects that basically renders them corrupt. I tried a lot of things (flushing out the UITabBar, re-creating the controllers array etc), but nothing worked.
I finally discovered that if you completely destroy the UITabBarItems and allocate new ones in their place, then those ones will work. :)
So my final solution to this was to add an extra condition in the viewDidLoad method of my controller that if the detected system was iOS 3, and there was already an array of UITabBarItems, it would go through each one, copy out all of the properties needed, destroy it, allocate a new one and then copy the old properties over to the new one.
I'm still going to keep an eye out for a better solution (I think there's a bit of overhead in this method), but thankfully at this stage, iOS 3 legacy support is becoming less and less of an issue. :)
Hey all. Something which has been bugging me quite a bit recently is this custom movie player I've put together. It's largely based on a working one, NGMoviePlayer.
The issue is this: I have the .xib in a UIKit-friendly resource bundle. When I call:
[MyMoviePlayerViewController initWithNibName:#"MyMoviePlayerViewController"
bundle:[NSBundle bundleWithPath:
[[NSBundle mainBundle] bundlePath]
stringByAppendingPathComponent:#"MyMoviePlayerViewController.bundle"]];
..on my custom class, and then access the view (thus calling loadView) it doesn't throw any errors, but nor does it actually load the outlets properly. I am presented with a white screen, and debugging shows that all visual elements are 0x0, but there was no error as would be expected.
EDIT: I've also now tried just loading the .xib outside of a resource bundle in my target app, and the same thing happens (white screen).
The particular ones I was looking for was either:
Could not load NIB <nibname>... if it wasn't found at all, or
...loaded the <nibname> NIB but the view outlet was not set if it was found but not connected properly
The xib is in the local app (I understand that static libs can't contain xibs). I've tried using this same resource bundle with the NGMoviePlayerDemo project provided by the author of NGMoviePlayer, and it does throw an error:
Could not load NIB in bundle:
'/Users/.../MyMoviePlayerViewController.bundle (not yet loaded)'
with name 'MyMoviePlayerViewController'
I have navigated to the path it displays for the bundle and there exists a MyMoviePlayerViewController.xib file at that location.
I've also tried using bundle:nil in case Xcode combined the resources of bundle directories with the main one for some reason. Both cases throw no error and display a white screen in my actual project. Both cases throw a Could not load NIB error in the NGMoviePlayerDemo project.
EDIT: I have tried the same .xib separate from a resource bundle in the NGMoviePlayerDemo app and it works fine.
All input is greatly appreciated.
Solution: Pay attention to Unknown class <classname> in Interface Builder file. messages.
I had the code for the movie player in a static lib, and the parent view controller for the movie player was being included in the project as an external header, but the subviews weren't included as headers, so they weren't being located properly. Because the only place they were being referenced in my target app was within the .xib file, there were no compile errors to do with those subclasses, but when it came time to load the .xib those classes could not be found, so none of their properties were set. And that just so happened to include all of the controls for the player, which probably then made the initialisation code silently fall over.
I merged all of the code and ivars from the subclasses into the parent movie player class, and it's working fine now :)