upgraded to xcode 4.2 now exc_bad_access on dimissModalViewcontroller - objective-c

Question

Hi I'm having a weird problem.
My app is based on the samplecode of "PageControl" (the Apple example).
It uses a horizontal scrollview in which most of the stuff is happening.
At he bottom I have a UIToolbar from which I call a modal viewcontroller.
On XCode 4 everything worked like a charm, after the upgrade to XCode 4.2 (with the new SDK) I get a "exc_bad_access" on dimissModalViewcontroller.
The funniest thing is that it does not happen rightaway but only after 2 or 3 times presenting and dismissing the modalViewcontroller.
To simplify things I went back to the original samplecode and tried to implement the modalVieWcontroler in that context. No luck so far.
In the original PageControl Code I changed the type of "ContentController" from NSObject to UIViewController like so:
#interface ContentController : UIViewController
{
NSArray *contentList;
}
I call presentModalViewcontroller in a sub class (from ContentController) named PhoneContentController like so:(I use a notification so I can call it from anywhere)
-(void) showExplanationsModal:(NSNotification*)notification{
ExplanationsViewController *xplViewController = [[[ExplanationsViewController alloc] initWithNibName:#"Explanations" bundle:nil]autorelease];
[self presentModalViewController:xplViewController animated:YES];
}
The dismissal of the modalViewcontroller is called from the modal view itself like so:
(the notification is used tot initiate some other stuff)
- (IBAction)onClose
{
[self dismissModalViewControllerAnimated:YES];
[[NSNotificationCenter defaultCenter]postNotificationName:#"dismissExplanationsModal" object:self];
}
This code works fine with iOS4 SDK but renders occasional excec_bad_access with iOS5 SDK.
When I compile the app with iOS4 SDK it also rus fine on iOS5 devices.
I tried using Zombies but this does not point to a specific over-released object.
I'm sort of stuck on this one for a few days already ...
I have put up a copy of a sample project that illustrates the problem here http://www.sesni.biz/pagecontrol.zip

Answer 1

It seems for me that problem is in the onClose method. Try first sending the message, without the object (this object will be invalidated soon).
- (IBAction)onClose
{
[[NSNotificationCenter defaultCenter]postNotificationName:#"dismissExplanationsModal" object:nil];
[self dismissModalViewControllerAnimated:YES];
}

Answer 2

Found the problem: I changed the type of ContententController from NSObject to UIViewcontroller. This worked fine with the iOS4 SDK but crashes with iOS5 SDK.