选择UICollectionView

Question

我正在关注教程并发出溢出UICollectionView。此外，我想对项目进行选择，然后出现新的UIViewController。

我可以知道如何做到这一点？ 我可以像UITable那样选择select index = 0,1或2等吗？ 代码显示正确NSLog但未转到其他UIViewController

 - (void)tapCell:(UITapGestureRecognizer *)inGestureRecognizer
{
    NSIndexPath *theIndexPath = [self.collectionView indexPathForCell:(UICollectionViewCell *)inGestureRecognizer.view];

    if (theIndexPath.row ==0) {
        NSLog(@"****");
        page *noteDetailViewControler = [[page alloc] initWithNibName:@"page" bundle:nil];    }
}

以下是完整代码：

@implementation CDemoCollectionViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.cellCount = 10;
    self.imageCache = [[NSCache alloc] init];

    [self.collectionView registerNib:[UINib nibWithNibName:NSStringFromClass([CCoverflowTitleView class]) bundle:NULL] forSupplementaryViewOfKind:@"title" withReuseIdentifier:@"title"];

    NSMutableArray *theAssets = [NSMutableArray array];
    NSURL *theURL = [[[NSBundle mainBundle] resourceURL] URLByAppendingPathComponent:@"Images"];
    NSEnumerator *theEnumerator = [[NSFileManager defaultManager] enumeratorAtURL:theURL includingPropertiesForKeys:NULL options:NSDirectoryEnumerationSkipsPackageDescendants | NSDirectoryEnumerationSkipsHiddenFiles errorHandler:NULL];
    for (theURL in theEnumerator)
    {
        if ([[theURL pathExtension] isEqualToString:@"jpg"])
        {
            [theAssets addObject:theURL];
        }
    }
    self.assets = theAssets;
    self.cellCount = self.assets.count;
}

#pragma mark -

- (void)updateTitle
{
    // Asking a collection view for indexPathForItem inside a scrollViewDidScroll: callback seems unreliable.
    //  NSIndexPath *theIndexPath = [self.collectionView indexPathForItemAtPoint:(CGPoint){ CGRectGetMidX(self.collectionView.frame) + self.collectionView.contentOffset.x, CGRectGetMidY(self.collectionView.frame) }];
    NSIndexPath *theIndexPath = ((CCoverflowCollectionViewLayout *)self.collectionView.collectionViewLayout).currentIndexPath;
    if (theIndexPath == NULL)
    {
        self.titleView.titleLabel.text = NULL;
    }
    else
    {
        NSURL *theURL = [self.assets objectAtIndex:theIndexPath.row];

        self.titleView.titleLabel.text = [NSString stringWithFormat:@"%@", theURL.lastPathComponent];
    }
}

#pragma mark -

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section;
{
    return(self.cellCount);
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath;
{
    CDemoCollectionViewCell *theCell = [self.collectionView dequeueReusableCellWithReuseIdentifier:@"DEMO_CELL" forIndexPath:indexPath];

    if (theCell.gestureRecognizers.count == 0)
    {
        [theCell addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapCell:)]];
    }

    theCell.backgroundColor = [UIColor colorWithHue:(float)indexPath.row / (float)self.cellCount saturation:0.333 brightness:1.0 alpha:1.0];

    if (indexPath.row < self.assets.count)
    {
        NSURL *theURL = [self.assets objectAtIndex:indexPath.row];
        UIImage *theImage = [self.imageCache objectForKey:theURL];
        if (theImage == NULL)
        {
            theImage = [UIImage imageWithContentsOfFile:theURL.path];

            [self.imageCache setObject:theImage forKey:theURL];
        }

        theCell.imageView.image = theImage;
        theCell.reflectionImageView.image = theImage;
        theCell.backgroundColor = [UIColor clearColor];
    }

    return(theCell);
}

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
    CCoverflowTitleView *theView = [self.collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"title" forIndexPath:indexPath];
    self.titleView = theView;
    [self updateTitle];
    return(theView);
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    [self updateTitle];
}

#pragma mark -

- (void)tapCell:(UITapGestureRecognizer *)inGestureRecognizer
{
    NSIndexPath *theIndexPath = [self.collectionView indexPathForCell:(UICollectionViewCell *)inGestureRecognizer.view];

    if (theIndexPath.row ==0) {
        NSLog(@"****");
        page *noteDetailViewControler = [[page alloc] initWithNibName:@"page" bundle:nil];    }
}


@end

Answer 1

尝试使用以下UICollectionViewDelegate函数：

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath;

如果您选择了该选项，则可以使用以下函数来处理它：

- (void)selectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated scrollPosition:(UICollectionViewScrollPosition)scrollPosition;
- (void)deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated;