应用程序仅在我第一次旋转手机时崩溃（EXC_BAD_ACCESS）。在它的所有肉汁之后的任何时候。它也只会在设备上崩溃。模拟器一切都很好。
#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 tap 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
答案 0 :(得分：1)
在viewDidLoad中，您分配imageView，并在最后解除分配，因此imageView的保留计数为0. imageView已被解除分配，这就是为什么您希望下次访问EXC_BAD_ACCESS时收到imageView。您将[imageView dealloc]排除在viewDidLoad方法之外，一切正常。
我注意到了另一件事：您忘了在-(void)dealloc中取消分配滚动视图。