我正在水平集合视图中显示从服务器接收的动态图像。当我设置集合视图时,我设置了:
-(void)setupCollectionView{
[self setupPageControlView];
self.screensCollectionView.delegate=self;
self.screensCollectionView.dataSource=self;
[self.screensCollectionView registerNib:[UINib nibWithNibName:@"FGAppScreensCollectionViewItemCell" bundle:nil] forCellWithReuseIdentifier:@"screenCell"];
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
[flowLayout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
[flowLayout setMinimumInteritemSpacing:0.0f];
[flowLayout setMinimumLineSpacing:0.0f];
[flowLayout setItemSize:CGSizeMake(165, 255)];
//[self.screensCollectionView setPagingEnabled:YES];
[self.screensCollectionView setCollectionViewLayout:flowLayout];
}
对于 cellForRowAtIndexPath 我下载如下图像:
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
static NSString *cellIdentifier = @"screenCell";
FGAppScreensCollectionViewItemCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:[self.imageURLArray objectAtIndex:indexPath.row]]];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[spinner startAnimating];
[spinner setFrame:CGRectMake(50, 100, 20, 20)];
[cell.contentView addSubview:spinner];
[cell.screenImageView setImageWithURLRequest:urlRequest placeholderImage:nil success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {
//STOP THE SPINNER
for (UIView* view in [cell.contentView subviews]) {
if ([view isKindOfClass:[UIActivityIndicatorView class]]) {
[view removeFromSuperview];
}
}
cell.screenImageView.image = image;
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
//
}];
[cell.screenImageView setImageWithURL:[NSURL URLWithString:[self.imageURLArray objectAtIndex:indexPath.row]]];
if (self.delegate) {
UITapGestureRecognizer* g = [[UITapGestureRecognizer alloc] initWithTarget:self.delegate action:@selector(showPopUpImageView:)];
[cell.screenImageView addGestureRecognizer:g];
}
return cell;
}
然而有肖像和风景图像显示在集合视图中。肖像图像显示得很好,但风景图像在集合视图中显得很小。我需要做的是根据图像大小调整单元格大小,以便它们填充正确的宽高比?
我添加了如下所示的方法,但问题是它在开始时立即被所有单元格调用,并且一旦我在 cellForRowAtIndexPath 方法中下载图像就不会被调用:
- (CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(165, 255);
}
因此,我想知道如何实现此功能,请告诉我是否需要这方面的更多信息?