"EXC_BAD_ACCESS" when switch too fast between an tableView and a mapView - iphone

Question

I have a tableView with an button to push a mapView. The push and back actions generally work fine. If I switch quickly between these two views, "EXC_BAD_ACCESS" error will appear.
MapViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
self.mapView.delegate = self;
UIButton *btnL = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 40.0, 40.0)];
[btnL setImage:[UIImage imageNamed:#"back.png"] forState:UIControlStateNormal];
[btnL addTarget:self.navigationController action:#selector(popViewControllerAnimated:) forControlEvents:UIControlEventTouchDown];
self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] initWithCustomView:btnL] autorelease];
[btnL release];
self.whereAmIAnnotation = [[[WhereAmIAnnotation alloc] init] autorelease];
if (!self.mapView || !self.whereAmIAnnotation) {
NSLog(#"mapview : %#", self.mapView);
NSLog(#"whereAmIAnnotation : %#",self.whereAmIAnnotation);
// will never enter in to here
}
[self.mapView addAnnotation:self.whereAmIAnnotation];
}
If I comment [self.mapView addAnnotation:self.whereAmIAnnotation]; , there is no "EXC_BAD_ACCESS" anymore.
Any answers and comments will be appreciated. Thanks in advance!
Edit 2
main.m
#import <UIKit/UIKit.h>
#import "AppDelegate.h"
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
// "EXC_BAD_ACCESS" error message shows here
}
}
Edit 3:
the whereAmIAnnotation is declared here:
MapViewController.m
#interface AddrCoordinateAdjustMapViewController()
#property (retain) WhereAmIAnnotation *whereAmIAnnotation;
#end
#implementation MapViewController
#synthesize whereAmIAnnotation;
Edit 4:
Error message is as following:
2012-07-30 15:56:19.735 myApp[13584:707] *** -[MapViewController respondsToSelector:]: message sent to deallocated instance 0x10195e80
It usually crashes when i switch back to the tableView while the annotationView is dropping.

Answer 1

Have you removed yourself as delegate of the mapview?
self.mapview.delegate = nil;
try removing it at viewWilldisappear or whenever you consider necessary as you might need it later if you have pushed a view controller and will return to the view later.
In a nutshell, remove it when your view cannot respond to the delegate which is why you got the EXC_BAD_ACCSS. it sent a message to your view but it was already released from memory.

Answer 2

Do you release and set to nil all your IBOutlets in the viewDidUnload? So at least you should do:
- (void)viewDidUnload {
self.mapView = nil;
[super viewDidUnload];
}
Generally in ViewDidUnload you should release and set to nil, any view objects that are created from a Nib file or allocated in your ViewDidLoad method

Answer 3

I would suggest to check whether self.whereAmIAnnotation isnt already released by at the time you add it to mapView. That might be one reason for the BAD_ACCESS you receive.

Answer 4

I had similar problem and my solution was to remove all overlays from the map before popping controller from UINavigationController. I was using OpenStreetMap.