UICollectionView Crashes when Cell is Touched - ios

Question

I have a UICollectionView with a custom class subclassed to UICollectionViewCell showing pictures from within the app. It loads fine, but if any cell is even barely touched, the app crashes. There is no error message in the Console, and nothing shows if I put in an Exception breakpoint either. The code for the view controller containing the Collection View is:
#import "ImagePicker.h"
#import "CMFGalleryCell.h"
#interface ImagePicker ()
#property (nonatomic, weak) IBOutlet UICollectionView *collectionView;
#property (nonatomic, strong) NSArray *dataArray;
#end
#implementation ImagePicker
#synthesize dataArray, collectionView;
- (void)viewDidLoad {
[super viewDidLoad];
self.title = #"Choose Image";
[self loadImages];
[self setupCollectionView];
// Do any additional setup after loading the view from its nib.
}
-(void)setupCollectionView {
[self.collectionView registerClass:[CMFGalleryCell class] forCellWithReuseIdentifier:#"cellIdentifier"];
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
[flowLayout setScrollDirection:UICollectionViewScrollDirectionVertical];
[flowLayout setMinimumInteritemSpacing:0.0f];
[flowLayout setMinimumLineSpacing:0.0f];
[self.collectionView setPagingEnabled:YES];
[self.collectionView setCollectionViewLayout:flowLayout];
}
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return [self.dataArray count];
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
CMFGalleryCell *cell = (CMFGalleryCell *)[collectionView dequeueReusableCellWithReuseIdentifier:#"cellIdentifier" forIndexPath:indexPath];
NSString *imageName = [self.dataArray objectAtIndex:indexPath.row];
[cell setImageName:imageName];
[cell updateCell];
return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"Chose%ld", (long)indexPath.row);
}
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return CGSizeMake(185, 185);
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 1.0;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 1.0;
}
// Layout: Set Edges
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
// return UIEdgeInsetsMake(0,8,0,8); // top, left, bottom, right
return UIEdgeInsetsMake(0,0,0,0); // top, left, bottom, right
}
-(void)loadImages {
NSString *sourcePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"inviteimages"];
self.dataArray = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:sourcePath error:NULL];
NSLog(#"%#", self.dataArray);
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
The custom Cell is:
#import "CMFGalleryCell.h"
#interface CMFGalleryCell()
#property (strong, nonatomic) IBOutlet UIImageView *imageView;
#end
#implementation CMFGalleryCell
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
NSArray *arrayOfViews = [[NSBundle mainBundle] loadNibNamed:#"CMFGalleryCell" owner:self options:nil];
if ([arrayOfViews count] < 1) {
return nil;
}
if (![[arrayOfViews objectAtIndex:0] isKindOfClass:[UICollectionViewCell class]]) {
return nil;
}
self = [arrayOfViews objectAtIndex:0];
}
return self;
}
-(void)updateCell {
NSString *sourcePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"inviteimages"];
NSString *filename = [NSString stringWithFormat:#"%#/%#", sourcePath, self.imageName];
UIImage *image = [UIImage imageWithContentsOfFile:filename];
[self.imageView setImage:image];
[self.imageView setContentMode:UIViewContentModeScaleAspectFill];
}
#end
What is going on causing it to crash if a cell is touched? If I touch the space between cells, I can get it to scroll, but any touch at all of the cell crashes.
Screenshot of crash without zombies:
Screenshot of crash with zombies:

Answer 1

You said you app will crash when cell is touched but you haven't implemented the cell select delegate method but written only cell deselect delegate method. Try this
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
And insert a breakpoint inside the same method to debug. If break point is not called then something else is the problem

Answer 2

Maybe problem is in your View Controller class:
#property link to ImagePicker can be weak, and you, for example, remove it from superview. After this, ImagePicker object will be deallocated.
Try to replace
#property (weak, nonatomic) ImagePicker *someImagePicker
with
#property (strong, nonatomic) ImagePicker *someImagePicker
Can you share code from your UIViewController?