App crashes when I rotate phone for the first time

App only crashes the first time i rotate my phone (EXC_BAD_ACCESS). Anytime after its all gravy. It only crashes on device too. Simulator everything is good.

#import "ImageViewController.h"
#define degreesToRadian(x) (M_PI * (x) / 180.0)
#define ZOOM_VIEW_TAG 100
#define ZOOM_STEP 1.5

@interface ImageViewController (UtilityMethods)
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center;
@end

@implementation ImageViewController
@synthesize imageView,url, enableLandscapeOrientation;

/*
 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
    }
    return self;
}
*/


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    // set up main scroll view
    imageScrollView = [[UIScrollView alloc] initWithFrame:[[self view] bounds]];
    [imageScrollView setBackgroundColor:[UIColor blackColor]];
    [imageScrollView setDelegate:self];
    [imageScrollView setBouncesZoom:YES];
    [[self view] addSubview:imageScrollView];

    // add touch-sensitive image view to the scroll view
    imageView = [[AsyncImageView alloc]initWithFrame:[self.view bounds]];
    if (enableLandscapeOrientation) {
        imageView.showGhost = YES;
    }
    [imageView loadImageFromURL:self.url];
    [imageView setTag:ZOOM_VIEW_TAG];
    [imageView setUserInteractionEnabled:YES];
    [imageScrollView setContentSize:[imageView frame].size];
    [imageScrollView addSubview:imageView];
    [imageView release];

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
    UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTwoFingerTap:)];

    [doubleTap setNumberOfTapsRequired:2];
    [twoFingerTap setNumberOfTouchesRequired:2];

    [imageView addGestureRecognizer:singleTap];
    [imageView addGestureRecognizer:doubleTap];
    [imageView addGestureRecognizer:twoFingerTap];

    [singleTap release];
    [doubleTap release];
    [twoFingerTap release];

    // calculate minimum scale to perfectly fit image width, and begin at that scale
    float minimumScale = [imageScrollView frame].size.width  / [imageView frame].size.width;
    [imageScrollView setMinimumZoomScale:minimumScale];
    [imageScrollView setMaximumZoomScale:4.0f];
    //[imageScrollView setZoomScale:minimumScale];

    //[imageScrollView setMinimumZoomScale:0.5f];
    //[imageScrollView setMaximumZoomScale:2.0f];



    //[self.imageView loadImageFromURL:self.url];
}



// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {

    if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft ||interfaceOrientation == UIInterfaceOrientationLandscapeRight) {

        imageScrollView.frame = CGRectMake(0,0,480,300); //self.view.bounds;
        imageView.frame = CGRectMake(0,0,480,300); //self.view.bounds;
    }
    else {
        imageScrollView.frame = CGRectMake(0,0,320,460); 
        imageView.frame = CGRectMake(0,0,320,460); 
    }


    //return (interfaceOrientation == UIInterfaceOrientationPortrait);
    if (enableLandscapeOrientation) {
        [[self navigationController] setNavigationBarHidden:UIInterfaceOrientationIsLandscape(interfaceOrientation) animated:YES];
        return YES;
    }
    else {
        return NO;
    }
}


- (void)dealloc {
    [imageView release];imageView=nil;
    [url release];url=nil;
    [super dealloc];
}

#pragma mark UIScrollViewDelegate methods

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return [imageScrollView viewWithTag:ZOOM_VIEW_TAG];
}

/************************************** NOTE **************************************/
/* The following delegate method works around a known bug in zoomToRect:animated: */
/* In the next release after 3.0 this workaround will no longer be necessary      */
/**********************************************************************************/
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale {
    [scrollView setZoomScale:scale+0.01 animated:NO];
    [scrollView setZoomScale:scale animated:NO];
}

#pragma mark Utility methods

- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center {

    CGRect zoomRect;

    // the zoom rect is in the content view's coordinates. 
    //    At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds.
    //    As the zoom scale decreases, so more content is visible, the size of the rect grows.
    zoomRect.size.height = [imageScrollView frame].size.height / scale;
    zoomRect.size.width  = [imageScrollView frame].size.width  / scale;

    // choose an origin so as to get the right center.
    zoomRect.origin.x    = center.x - (zoomRect.size.width  / 2.0);
    zoomRect.origin.y    = center.y - (zoomRect.size.height / 2.0);

    return zoomRect;
}

- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
    // single t开发者_如何学编程ap does nothing for now
}

- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
    // double tap zooms in
    float newScale = [imageScrollView zoomScale] * ZOOM_STEP;
    CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
    [imageScrollView zoomToRect:zoomRect animated:YES];
}

- (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer {
    // two-finger tap zooms out
    float newScale = [imageScrollView zoomScale] / ZOOM_STEP;
    CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
    [imageScrollView zoomToRect:zoomRect animated:YES];
}




@end

In viewDidLoad you allocate the imageView and at the end you deallocate it, so the retain count of imageView is 0. imageView has been deallocated, and that's why you receive a EXC_BAD_ACCESS as soon as you want to access imageView the next time. You put the [imageView dealloc] out of your viewDidLoad method and everything should work fine.

And just another thing I noticed: You forgot to deallocate the scroll view in -(void)dealloc.