StackOverflow2013

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copied!<p>The way you're trying to do this is incorrect. You need to keep a reference to the selected cell or cells in a property. In this example, I use an array to hold index paths of the selected cells, then check whether the index path passed in to cellForItemAtIndexPath is contained in that array. I unselect the cell if you click on one that's already selected:</p> <pre><code>@interface ViewController () @property (strong,nonatomic) NSArray *theData; @property (strong,nonatomic) NSMutableArray *paths; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; self.paths = [NSMutableArray new]; self.theData = @[@"One",@"Two",@"Three",@"Four",@"Five",@"Six",@"Seven",@"Eight"]; [self.collectionView registerNib:[UINib nibWithNibName:@"CVCell" bundle:nil] forCellWithReuseIdentifier:@"cvCell"]; UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init]; [flowLayout setScrollDirection:UICollectionViewScrollDirectionVertical]; [self.collectionView setCollectionViewLayout:flowLayout]; } -(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section { return self.theData.count; } -(CVCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath { static NSString *cellIdentifier = @"cvCell"; CVCell *cell = (CVCell *) [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath]; cell.backgroundColor = [UIColor whiteColor]; cell.label.text = self.theData[indexPath.row]; if ([self.paths containsObject:indexPath]) { [cell.iv setHidden:NO]; // iv is an IBOutlet to an image view in the custom cell }else{ [cell.iv setHidden:YES]; } return cell; } -(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath { if ([self.paths containsObject:indexPath]) { [self.paths removeObject:indexPath]; }else{ [self.paths addObject:indexPath]; } [self.collectionView reloadItemsAtIndexPaths:@[indexPath]]; } - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath { return CGSizeMake(150, 150); } </code></pre>

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