UICollectionView自定義水平分頁布局

Question

[！[collectionview示例] [1]] [1]

我正在嘗試使用集合視圖來模擬這種行為。 我從使用這種方法開始，它使我更加接近。 盡管在水平分頁CollectionView上向右滑動時，內容向左移。 單元之間的間距也關閉。 我相信它需要自定義布局，但不確定。

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

    return CGSize(width: collectionView.frame.width - 20, height: collectionView.frame.height - 20)

}

Answer 1

它取決於3個因素1）截面插圖2）單元間距3）單元大小

每個方面的任何更改都必須針對您的情況更改其他

1）左右設置20

2）將像元間距設置為10

func collectionView(collectionView: UICollectionView,
    layout collectionViewLayout: UICollectionViewLayout,
    minimumInteritemSpacingForSectionAtIndex section: Int) -> CGFloat {
        return 10
}
func collectionView(collectionView: UICollectionView, layout
    collectionViewLayout: UICollectionViewLayout,
    minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
        return 10
}

3）設置像元大小

func collectionView(collectionView: UICollectionView,
    layout collectionViewLayout: UICollectionViewLayout,
    sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        return CGSize(width: collectionView.frame.width / 1.15 ,height: collectionView.frame.height)
}

4）這將使屏幕中的單元格居中

func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

    let pageWidth:CGFloat = scrollView.frame.width / 1.15 + cellSpacing ;

    let currentOffset:CGFloat = scrollView.contentOffset.x;
    let targetOffset:CGFloat = targetContentOffset.memory.x
    var newTargetOffset:CGFloat = 0;

    if targetOffset > currentOffset
    {
        newTargetOffset = ceil(currentOffset / pageWidth) * pageWidth;
    }
    else
    {
        newTargetOffset = floor(currentOffset / pageWidth) * pageWidth;
    }

    if newTargetOffset < 0
    {
        newTargetOffset = 0
    }
    else if newTargetOffset > scrollView.contentSize.width
    {
    newTargetOffset = scrollView.contentSize.width;
    }

    targetContentOffset.memory.x = currentOffset

    scrollView.setContentOffset(CGPointMake(newTargetOffset, 0), animated: true)

}

Answer 2

我對@Mohamed的解決方案進行了一些更改，它對我來說非常有效：

func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

    let cellSpacing: CGFloat = self.collectionView(self.collectionView, layout: self.collectionView.collectionViewLayout, minimumInteritemSpacingForSectionAt: 0)
    let pageWidth: CGFloat = self.pageWidth + cellSpacing

    let currentOffset = scrollView.contentOffset.x
    let targetOffset = targetContentOffset.pointee.x
    targetContentOffset.pointee.x = currentOffset

    var pageNumber = 0
    if targetOffset > currentOffset {
        pageNumber = Int(ceil(currentOffset / pageWidth))
    }
    else {
        pageNumber = Int(floor(currentOffset / pageWidth))
    }

    let indexPath = IndexPath(row: pageNumber, section: 0)
    self.collectionView.scrollToItem(at: indexPath, at: UICollectionView.ScrollPosition.centeredHorizontally, animated: true)
}