4

で「エンドレススクロール」を実装しようとしていUICollectionViewます。

このチュートリアルのようにデータ配列をバッファリングすることでこれを行います

次に、次の方法でdidEndDisplayingCellofを実装します。UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath{
if (self.galleryArray.count > 0) {

    NSIndexPath *newIndexPath = indexPath;

    if (self.specialHeaderView.bannerView.scrollDirection == left) {
        newIndexPath = [NSIndexPath indexPathForItem:indexPath.row - 1 inSection:indexPath.section];
    } else if (self.specialHeaderView.bannerView.scrollDirection == right) {
        newIndexPath = [NSIndexPath indexPathForItem:indexPath.row + 1 inSection:indexPath.section];
    }

    if (newIndexPath.row == (self.galleryArray.count - 1)) {
        // user is scrolling to the right from the last item to the 'fake' item 1.
        // reposition offset to show the 'real' item 1 at the left-hand end of the collection view

        newIndexPath = [NSIndexPath indexPathForItem:1 inSection:indexPath.section];

        [self.bannerCollectionView scrollToItemAtIndexPath:newIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];
        return;

    }

    //        if (scrollView.contentOffset.x == self.collectionView.frame.size.width)  {
    if (newIndexPath.row == 0) {
        // user is scrolling to the left from the first item to the fake 'item N'.
        // reposition offset to show the 'real' item N at the right end end of the collection view

        newIndexPath = [NSIndexPath indexPathForItem:([self.galleryArray count] -2) inSection:indexPath.section];

        [self.bannerCollectionView scrollToItemAtIndexPath:newIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];

    }


}

}

問題は、メソッドが呼び出され、コレクション ビューがデリゲートメソッドdidEndDisplayingCellを介してセルを要求するたびに、セルが非表示に戻ることです。CellForItemAtIndexPath

これが私のCellForItemAtIndexPath実装です：

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
SpecialBannerCell *specialBannerCell = (SpecialBannerCell *)[collectionView dequeueReusableCellWithReuseIdentifier:GalleryCellIdentifier forIndexPath:indexPath];
if (specialBannerCell.hidden) {

}
Benefit *benefit = [self.galleryArray objectAtIndex:indexPath.row];
[specialBannerCell.imageBanner setImageWithURL:[NSURL URLWithString:benefit.imageIphoneUrl] placeholderImage:[UIImage imageNamed:@"photo_loader"]];
return specialBannerCell;

}

ここで何が間違っていますか？

4

1 に答える 1

0

理由はわかりませんが、 didEndDisplayingCell メソッドの代わりに UIScrollViewDelegate メソッドを使用すると、セルが非表示にならず、すべてが完璧に機能します。

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {

    if (self.galleryArray.count > 0) {

    NSIndexPath *indexPath = self.currentIndexPath;

    NSIndexPath *newIndexPath = indexPath;

    if (newIndexPath.row == (self.galleryArray.count - 1)) {
        // user is scrolling to the right from the last item to the 'fake' item 1.
        // reposition offset to show the 'real' item 1 at the left-hand end of the collection view

        newIndexPath = [NSIndexPath indexPathForItem:1 inSection:indexPath.section];

        self.currentIndexPath = newIndexPath;

        [self.bannerCollectionView scrollToItemAtIndexPath:newIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];
        return;

    }

    if (newIndexPath.row == 0) {
        // user is scrolling to the left from the first item to the fake 'item N'.
        // reposition offset to show the 'real' item N at the right end end of the collection view

        newIndexPath = [NSIndexPath indexPathForItem:([self.galleryArray count] -2) inSection:indexPath.section];

        self.currentIndexPath = newIndexPath;

        [self.bannerCollectionView scrollToItemAtIndexPath:newIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];

    }


}

}

于 2014-06-23T06:07:01.723 に答える