Swift下使用UICollectionView 实现长按拖拽功能

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 }()

 //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) }

 //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 }

//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  }) }

 func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {  if indexPath.section > 0 {   // 更新数据   let obj = recommendArr[indexPath.item]   recommendArr.remove(at: indexPath.item)   selectedArr.append(obj)   //移动方法   collectionView.moveItem(at: indexPath, to: NSIndexPath(item: selectedArr.count - 1, section: 0) as IndexPath)  } else {   if isEdite {    if indexPath.item == 0 {return}    // 更新数据    let obj = selectedArr[indexPath.item]    selectedArr.remove(at: indexPath.item)    recommendArr.insert(obj, at: 0)    //移动方法    collectionView.moveItem(at: indexPath, to: NSIndexPath(item: 0, section: 1) as IndexPath)   } else {    if switchoverCallback != nil {     //处理点击的闭包     switchoverCallback!(selectedArr, recommendArr, indexPath.item)     _ = navigationController?.popViewController(animated: true)    }   }  } }

collectionView.moveItem(at: indexPath, to: NSIndexPath(item: 0, section: 1) as IndexPath)

collectionView.moveItem(at: indexPath!, to: targetIndexPath!)

 // Support for reordering @available(iOS 9.0, *) open func beginInteractiveMovementForItem(at indexPath: IndexPath) -> Bool // returns NO if reordering was prevented from beginning - otherwise YES @available(iOS 9.0, *) open func updateInteractiveMovementTargetPosition(_ targetPosition: CGPoint) @available(iOS 9.0, *) open func endInteractiveMovement() @available(iOS 9.0, *) open func cancelInteractiveMovement()