i had 2 scene, "List Scene" and "Details Scene". After Click the Item on "List Scene", it will go to "Details Scene". In the "Details Scene", i had some animation, anime the Image keep repeat move from left to right or right to left. After i go back "List Scene", the scene looking like "hanging", i cant do any thing for the List any more(like scrolling). After i check out, found out the "Left to Right,Right To Left" animation is still running on behind. So now i assume, because the previous scene i still running, so current scene not able to detect my finger.
so my question is, is that got any way can remove/release/dismiss the previous scene after popviewcontrolleranimated?
below is the code i testing now.
-(void)viewWillDisappear:(Bool)animated{
[super viewWillDisappear:animated];
self.imagePanViewController = nil; //target is this viewcontroller, this viewcontroller handle the animation
[self.navigationController setNavigationBarHidden:NO animated:YES];
}
i had try use some way like "dismissViewController", release, controller = nil, and so on. but the results is still fail and animation keep running on behind.
is that any one can give me some guideline or hints? thanks alot!
I believe myidleTimer is an NSTimer. NSTimer retains its target.
You can follow the below link to properly invalidate it
Best time to invalidate NSTimer inside UIViewController to avoid retain cycle
Also make the timer having weak reference.
I've been working with iCarousel for about a week now, and I've had great success with outside testing. Now, I'm trying to put it into my app and it won't display the views. I was using UIViews to be displayed originally, which was working fine in my test programs, but due to sheer frustration im going as basic as possible and have literally just copied everythinng over from the examples. I connected the delegate and datasource, I called reloadData, ive done everything i could possibly find to fix this and it's not getting fixed. here's some code implementing the actual icarousel:
- (IBAction)coverflowPressed:(id)sender {
self.carousel = [[iCarouselExampleViewController alloc]
initWithNibName:#"iCarouselExampleViewController" bundle:nil];
[self presentViewController:self.carousel animated:YES completion:nil];
}
The rest of the code is basically copied from an example that works outside my app. As i mentioned, i DID connect the delegate and dataSource. It displays the background just fine, but it's like the carousel is empty; it has no items in it, and yes, there ARE items in it. any ideas for me?
EDIT
Maybe i connected the delegate and datasource wrong. could somebody maybe explain how to do that from an app thats already halfway through production?
Breakpoints prove that it's never reaching carousel-specific functions, like viewForItemAtIndex or even awakeFromNib. viewDidLoad is called, so i set the delegate and datasource in there. Originally they were set in the nib but i changed it to programmatically. anyways heres my viewdidload method:
- (void)viewDidLoad {
[super viewDidLoad];
self.carousel.delegate = self;
self.carousel.dataSource = self;
//configure carousel
_carousel.type = iCarouselTypeCoverFlow2;
}
it reaches the end of this function but it never goes any farther with it...
I'm struggling to find what’s going wrong with my code. I’m trying to dismiss a UITableViewController using delegate but getting a EXC_BAD_ACCESS.
The UITableViewController is called (modal segue) from the root view controller of my application. When the rootViewController try to dismiss the UITableViewController everything seems to be all right because the rootViewController view is presented but after a milisecond the error arise.
- (void) dismissFormAViewController: (FormAViewController*) vc{
[vc dismissViewControllerAnimated:YES completion:^{
NSLog(#"complete.");
}];
}
I can see the string Complete on my console.
typically this means that you are accessing some memory that isn't a valid object anymore,
to debug turn on zombies in your run scheme, this will give you at least the class that is being accessed... Then if it is not obvious, you can back track with malloc logging
Ok, here is the deal, I hate putting out questions about my debugging and crashes. Because I usually handle them myself, but I just cannot get my way around this, even after viewing multiple questions already.
Ok so here is the problem, I find my app randomly on and off crashing with this stack trace:
*** -[ViewController respondsToSelector:]: message sent to deallocated instance 0x1e5d2ef0
Where ViewController can vary, sometimes the place where my code crashes, has NO relevance to that particular ViewController and doesn't own or call it.
Also, to get that console trace, I have enabled Zombies, otherwise I would get no console print at all, I would only get: objc_msgSend, which I know means I am messaging something that is released. But I cannot find where that is... I am really stuck! Usually I always debug my crashes, so I am really stuck on this.
Again, this crashes in different places at different times, on and off. And the place it crashes has almost no relevance to the ViewController. And I find this very confusing.
Do you need any of my code? I have a lot of files and since it is crashing in different places, distributing my code will be a mess!
I have tried to add symbolic breakpoints with no luck, and Zombies is not available on the Instruments application for iOS. I cannot run my app on the simulator as it has unsupportive architecture frameworks for it.
Thanks everyone...
Use Instruments to track down deallocated instance errors. Profile your application (Cmd ⌘+I) and choose Zombies template. After your application is running, try to crash it. You should get something like that:
Click on the arrow next to address in the popover to show object that was called after it was deallocated.
You should see now every call that has changed retain count of this object. This could be because sending directly retain/release messages as well as draining autorelease pools or inserting into NSArrays.
RefCt column shows retainCount after action was invoked and Responsible Caller shows class name and method in which it was performed. When you double click on any retain/release, instruments will show you line of code where this was performed (If this isn't working, you can examine call by selecting it and choosing its counterpart in Extended Detail pane):
This will let you examine all the retainCount lifecycle of object and probably you'll find your problem right away. All you got to do is find missing retain for latest release.
had a similar problem. In my case a viewController needed to get navigationController events, so it was registering as the navigation controller delegate:
self.navigationController.delegate = self;
The crash occurs when that controller was dealloc'ed but was still the delegate for the view controller. Adding this code in dealloc had no effect:
-(void) dealloc
{
if (self.navigationController.delegate == self)
{
self.navigationController.delegate = nil;
}
because at the point that dealloc is called, the view controller has already been removed from the view hierarchy, so self.navigationController is nil, so the comparison is guaranteed to fail! :-(
The solution was to add this code to detect the VC leaving the view hierarchy just before it actually does so. It uses a method introduced in iOS 5 to determine when the view is being pop'ed and not pushed
-(void) viewWillDisappear:(BOOL) animated
{
[super viewWillDisappear:animated];
if ([self isMovingFromParentViewController])
{
if (self.navigationController.delegate == self)
{
self.navigationController.delegate = nil;
}
}
}
No more crashes!
For anyone who can't solve it, here are some other techniques:
https://stackoverflow.com/a/12264647/539149
https://stackoverflow.com/a/5698635/539149
https://stackoverflow.com/a/9359792/539149
https://stackoverflow.com/a/15270549/539149
https://stackoverflow.com/a/12098735/539149
You can run Instruments in Xcode 5 by clicking the project popup->Edit Scheme...Profile ->Instrument and choose Allocations or Leaks, then profile your app, then stop Instruments, click the info button in Allocations and "Enable NSZombie Detection".
However, for the messages that come directly from the com.apple.main-thread, this probably won't reveal anything.
I banged my head on this for over two hours and the answer turned out to be an over-release, which I discovered by commenting out a copy of my project by brute force until I found the culprit:
[viewController release];
viewController = NULL;
The problem is that release doesn't set the variable to NULL.
That means that setting it to NULL calls release again, decrementing the refcount and freeing the memory immediately until later when the variables that reference viewController are finished with it.
So either enable ARC or make sure your project consistently uses release or NULL but not both. My preference is to use NULL because then there is no chance of referencing a zombie but it makes finding where objects are released more difficult.
I had met the same problem in iOS yesterday. I have made IAP in App "About" subview, and I have added Transaction Observer in "About" viewDidLoad. When I purchase for the first time, no problem, but after I back to main window and enter about subview to purchase again, the problem "message sent to deallocated instance" happened, and the App crashed.
- (void)viewDidLoad
{
[[SKPaymentQueue defaultQueue] addTransactionObserver:self]; object:nil];
}
After I remove Transaction Observer in dealloc, the problem is solved.
- (void)dealloc
{
// Even though we are using ARC, we still need to manually stop observing any
// NSNotificationCenter notifications. Otherwise we could get "zombie" crashes when
// NSNotificationCenter tries to notify us after our -dealloc finished.
[[SKPaymentQueue defaultQueue] removeTransactionObserver:self];
}
I had a very similar issue and I figured out it was due to navigation controller delegates set.
The below solved my issue,
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
if (self.navigationController.delegate != self) {
self.navigationController.delegate = self;
}
}
-(void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
if (self.navigationController.delegate == self) {
self.navigationController.delegate = nil;
}
}
Had the same problem in OS X.
To solve this not enough - (void)dealloc method as #SoftwareEvolved already said. But unfortunately - (void)viewWillDisappear is available only on version 10.10 and later.
I introduced custom method in my NSViewController subclass where set all the zombie-dangerous references to nil. In my case that was NSTableView properties (delegate and dataSource).
- (void)shutdown
{
self.tableView.delegate = nil;
self.tableView.dataSource = nil;
}
That's all. Each time I'm about to remove view from the superview need call this method.
I had the same Problem.It was difficult to find which delegate cause issue, because it does not indicate any line or code statement So I have try some way, Maybe it becomes helpful to you.
Open xib file and from file's owner, Select "show the connections inspector" right hand side menu. Delegates are listed, set them to nil which are suspected.
(Same as my case)Property Object like Textfield can create issue, So set its delegates to nil.
-(void) viewWillDisappear:(BOOL) animated{
[super viewWillDisappear:animated];
if ([self isMovingFromParentViewController]){
self.countryTextField.delegate = nil;
self.stateTextField.delegate = nil;
}
}
I just tracked down a crash I was having in my iOS app and it is related to willAnimateRotationToInterfaceOrientation being called before viewWillAppear.
I have an app with two views. Basically, when view1 disappears, I release some arrays, assuming they will be re-initialized when it re-appears in viewWillAppear.
However, if I change orientation in view2 then switch back to view1, this causes willAnimateRotationToInterfaceOrientation to happen before view1 has calledviewWillAppear and re-initialized everything and this causes a crash.
Is there any way to delay willAnimateRotationToInterfaceOrientation until after the view has appeared and everything has been re-initialized?
If not, the only solutions I can see are either not using willAnimateRotationToInterfaceOrientation (which results in an ugly looking orientation change) or not releasing my data when I switch from view1 to view2 which results in more memory being used than necessary.
Does anybody have any thoughts on what I should do?
You can use lazy-loading style code avoid your problem, like:
NSArray* someData;
-(void)somefun1{
if (!someData) {
[self loadData];
}
//use your data
}
-(void)somefun2{
if (!someData) {
[self loadData];
}
//use your data
}
-(void)loadData{
//some loading code
}
use lazy-loading style code you never need mind event calling order.