我正在尝试创建一个像Facebook菜单幻灯片动画POP框架的动画,或者完全像
InShorts App.
Android Documentation涵盖了这一点.但是在iOS中找不到任何提示.
我试过的是将单元格变换为
func tableView(tableView: UITableView,willDisplayCell cell: UITableViewCell,forRowAtIndexPath indexPath: NSIndexPath) {
UIView.animateWithDuration(0.1,animations: { () -> Void in
cell.transform = CGAffineTransformMakeScale(0.8,0.8)
})
}
但是这并不如预期的那样工作.我发现this一个我想要达到的目标.但它在UIView.如果我们在UITableViewCell中动画,我认为最适合我真的很感激有人愿意帮助这个问题. Here是我正在开展的启动项目
解决方法
这个效果可以使用UICollectionView获得.这是UICollectionViewFlowLayout类.
class UltravisualLayout: UICollectionViewLayout {
private var contentWidth:CGFloat!
private var contentHeight:CGFloat!
private var yOffset:CGFloat = 0
var maxAlpha:CGFloat = 1
var minAlpha:CGFloat = 0
var widthOffset:CGFloat = 35
var heightOffset:CGFloat = 35
private var cache = [UICollectionViewLayoutAttributes]()
private var itemWidth:CGFloat{
return (collectionView?.bounds.width)!
}
private var itemHeight:CGFloat{
return (collectionView?.bounds.height)!
}
private var collectionViewHeight:CGFloat{
return (collectionView?.bounds.height)!
}
private var numberOfItems:Int{
return (collectionView?.numberOfItemsInSection(0))!
}
private var dragOffset:CGFloat{
return (collectionView?.bounds.height)!
}
private var currentItemIndex:Int{
return max(0,Int(collectionView!.contentOffset.y / collectionViewHeight))
}
var nextItemBecomeCurrentPercentage:CGFloat{
return (collectionView!.contentOffset.y / (collectionViewHeight)) - CGFloat(currentItemIndex)
}
override func prepareLayout() {
cache.removeAll(keepCapacity: false)
yOffset = 0
for item in 0 ..< numberOfItems{
let indexPath = NSIndexPath(forItem: item,inSection: 0)
let attribute = UICollectionViewLayoutAttributes(forCellWithIndexPath: indexPath)
attribute.zIndex = -indexPath.row
if (indexPath.item == currentItemIndex+1) && (indexPath.item < numberOfItems){
attribute.alpha = minAlpha + max((maxAlpha-minAlpha) * nextItemBecomeCurrentPercentage,0)
let width = itemWidth - widthOffset + (widthOffset * nextItemBecomeCurrentPercentage)
let height = itemHeight - heightOffset + (heightOffset * nextItemBecomeCurrentPercentage)
let deltaWidth = width/itemWidth
let deltaHeight = height/itemHeight
attribute.frame = CGRectMake(0,yOffset,itemWidth,itemHeight)
attribute.transform = CGAffineTransformMakeScale(deltaWidth,deltaHeight)
attribute.center.y = (collectionView?.center.y)! + (collectionView?.contentOffset.y)!
attribute.center.x = (collectionView?.center.x)! + (collectionView?.contentOffset.x)!
yOffset += collectionViewHeight
}else{
attribute.frame = CGRectMake(0,itemHeight)
attribute.center.y = (collectionView?.center.y)! + yOffset
attribute.center.x = (collectionView?.center.x)!
yOffset += collectionViewHeight
}
cache.append(attribute)
}
}
//Return the size of ContentView
override func collectionViewContentSize() -> CGSize {
contentWidth = (collectionView?.bounds.width)!
contentHeight = CGFloat(numberOfItems) * (collectionView?.bounds.height)!
return CGSizeMake(contentWidth,contentHeight)
}
//Return Attributes whose frame lies in the Visible Rect
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
var layoutAttributes = [UICollectionViewLayoutAttributes]()
for attribute in cache{
if CGRectIntersectsRect(attribute.frame,rect){
layoutAttributes.append(attribute)
}
}
return layoutAttributes
}
override func shouldInvalidateLayoutForBoundsChange(newBounds: CGRect) -> Bool {
return true
}
override func targetContentOffsetForProposedContentOffset(proposedContentOffset: CGPoint,withScrollingVelocity velocity: CGPoint) -> CGPoint {
let itemIndex = round(proposedContentOffset.y / (dragOffset))
let yOffset = itemIndex * (collectionView?.bounds.height)!
return CGPoint(x: 0,y: yOffset)
}
override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? {
// Logic that calculates the UICollectionViewLayoutAttributes of the item
// and returns the UICollectionViewLayoutAttributes
return UICollectionViewLayoutAttributes(forCellWithIndexPath: indexPath)
}
}
这是演示项目link …
非常感谢这tutorial.
