导读
简单用Swift写了一个collectionview的拖拽点击排序效果;
拖拽排序是新闻类的App可以说是必有的交互设计，如今日头条，网易新闻等。
GitHub地址：https://www.easck.com/p>
效果
主要代码
手势长按移动
1.给CollectionViewCell添加一个长按手势.
private lazy var collectionView: UICollectionView = {
let clv = UICollectionView(frame: self.view.frame, collectionViewLayout: ChannelViewLayout())
clv.backgroundColor = UIColor.white
clv.delegate = self
clv.dataSource = self
clv.register(ChannelViewCell.self, forCellWithReuseIdentifier: ChannelViewCellIdentifier)
clv.register(ChannelHeaderView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: ChannelViewHeaderIdentifier)
let longPress = UILongPressGestureRecognizer(target: self, action: #selector(longPressGesture(_:)))
clv.addGestureRecognizer(longPress)
return clv
}()
2.开始长按时对cell进行截图或拷贝一个cell，并隐藏cell.
//MARK: - 长按开始
private func dragBegan(point: CGPoint) {
indexPath = collectionView.indexPathForItem(at: point)
if indexPath == nil || (indexPath?.section)! > 0 || indexPath?.item == 0
{return}
let item = collectionView.cellForItem(at: indexPath!) as? ChannelViewCell
item?.isHidden = true
dragingItem.isHidden = false
dragingItem.frame = (item?.frame)!
dragingItem.text = item!.text
//放大效果(此处可以根据需求随意修改)
dragingItem.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)
}
3.在手势移动的时候，找到目标是的indexPatch，再调用系统的api交换这个cell和隐藏cell的位置，并且更新数据.
//MARK: - 移动过程
private func drageChanged(point: CGPoint) {
if indexPath == nil || (indexPath?.section)! > 0 || indexPath?.item == 0 {return}
dragingItem.center = point
targetIndexPath = collectionView.indexPathForItem(at: point)
if targetIndexPath == nil || (targetIndexPath?.section)! > 0 || indexPath == targetIndexPath || targetIndexPath?.item == 0 {return}
// 更新数据
let obj = selectedArr[indexPath!.item]
selectedArr.remove(at: indexPath!.row)
selectedArr.insert(obj, at: targetIndexPath!.item)
//交换位置
collectionView.moveItem(at: indexPath!, to: targetIndexPath!)
//进行记录
indexPath = targetIndexPath
}
4.手势停止或取消时，移除view，显示隐藏cell. (这里手势取消也要掉用此方法)
//MARK: - 长按结束或取消
private func drageEnded(point: CGPoint) {
if indexPath == nil || (indexPath?.section)! > 0 || indexPath?.item == 0 {return}
let endCell = collectionView.cellForItem(at: indexPath!)
UIView.animate(withDuration: 0.25, animations: {
self.dragingItem.transform = CGAffineTransform.identity
self.dragingItem.center = (endCell?.center)!
}, completion: {
(finish) -> () in
endCell?.isHidden = false
self.dragingItem.isHidden = true
self.indexPath = nil
})
}
