我正在制作水平UICollectionView
,而在UICollectionViewCell
内我有滚动视图,在滚动视图中我有一个imageView。
我遇到的问题是,当我放大imageView时,scrollView会占用所有单元格大小,因此它不适合图像大小的高度和宽度。通过向上和向下滚动图像从scrollview中消失,我不知道我的代码中出了什么问题。
我的ColectionViewCell
代码:
class CollectionViewCell: UICollectionViewCell {
@IBOutlet var scrollView: UIScrollView!
@IBOutlet var ImageV: UIImageView!
}
CollectionView代码:
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! CollectionViewCell
cell.scrollView.contentMode = UIViewContentMode.ScaleAspectFit
cell.scrollView.delegate = self
cell.ImageV.image = UIImage(named: array[indexPath.row])
cell.ImageV.contentMode = UIViewContentMode.ScaleAspectFit
cell.scrollView.minimumZoomScale = 1
cell.scrollView.maximumZoomScale = 4;
cell.scrollView.contentSize = cell.ImageV.frame.size
return cell
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSize(width: self.collectionView.frame.size.width , height: self.collectionView.frame.size.height - 100)
}
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {
let indexPath = NSIndexPath(forItem: Int(currentIndex), inSection: 0)
if let cell1 = self.collectionView.cellForItemAtIndexPath(indexPath) {
let cell = cell1 as! CollectionViewCell
let boundsSize = cell.scrollView.bounds.size
var contentsFrame = cell.ImageV.frame
if contentsFrame.size.width < boundsSize.width{
contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2
}else{
contentsFrame.origin.x = 0
}
if contentsFrame.size.height < boundsSize.height {
contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2
}else{
contentsFrame.origin.y = 0
}
return cell.ImageV
}
return UIView()
}
func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
currentIndex = self.collectionView.contentOffset.x / self.collectionView.frame.size.width;
oldcell = currentIndex - 1
let indexPath = NSIndexPath(forItem: Int(oldcell), inSection: 0)
if let cell1 = self.collectionView.cellForItemAtIndexPath(indexPath) {
let cell = cell1 as! CollectionViewCell
cell.scrollView.zoomScale = 0
}
}
图片预览: https://i.imgur.com/Gr2p09A.gifv
我的项目在此处找到: https://drive.google.com/file/d/0B32ROW7V8Fj4RVZfVGliXzJseGM/view?usp=sharing
答案 0 :(得分:4)
首先,让我们从持有UIViewController
的{{1}}开始:
定义一个变量来保存集合视图布局:
UICollectionView
您必须覆盖var flowLayout:UICollectionViewFlowLayout = UICollectionViewFlowLayout()
,这将处理collectionView大小。
viewWillLayoutSubviews
此外,您还需要覆盖override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
flowLayout.itemSize = CGSize(width: view.frame.width, height:view.frame.height)
}
来处理每个新单元格的大小,以将其设置为默认大小:
viewDidLayoutSubviews
在 override func viewDidLayoutSubviews() {
if let currentCell = imageCollectionView.cellForItemAtIndexPath(desiredIndexPath) as? GalleryCell {
currentCell.configureForNewImage()
}
}
中将collectionView设置为与流布局水平:
ViewDidLoad
在 // Set up flow layout
flowLayout.scrollDirection = UICollectionViewScrollDirection.Horizontal
flowLayout.minimumInteritemSpacing = 0
flowLayout.minimumLineSpacing = 0
// Set up collection view
imageCollectionView = UICollectionView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height), collectionViewLayout: flowLayout)
imageCollectionView.translatesAutoresizingMaskIntoConstraints = false
imageCollectionView.registerClass(GalleryCell.self, forCellWithReuseIdentifier: "GalleryCell")
imageCollectionView.dataSource = self
imageCollectionView.delegate = self
imageCollectionView.pagingEnabled = true
view.addSubview(imageCollectionView)
imageCollectionView.contentSize = CGSize(width: 1000.0, height: 1.0)
方法中UICollectionView
只加载图片而不设置任何内容:
cellForItemAtIndexPath
现在让我们转到 cell.image = UIImage(named: array[indexPath.row])
类并在缩放时处理scrollView:
GalleryCell
我已经通过示例对其进行了测试,它应该通过scrollview来解决您的问题,并且@Spencevail主要解释了它为什么会被引发!
答案 1 :(得分:3)
您需要在滚动视图上设置contentInset
。发生的事情contentSize
的{{1}}最初设置为与屏幕尺寸相匹配。当您放大滚动视图时,contentSize会按比例扩展,因此当您放大时,在缩放时,照片上方和下方的黑色区域会在放大时展开。换句话说,您正在扩展区域的上方和下方区域你的形象可以去。如果您调整UIScrollView
,它将带来该死区,并且不允许滚动视图将图像移出窗口。
contentInset
这与我帮助管理的开源Cocoapod SwiftPhotoGallery几乎相同。看看SwiftPhotoGalleryCell
的代码,你应该很清楚如何做到这一点。 (如果你愿意,也可以随意使用cocoapod!)