swift 拖动按钮_Swift下使用UICollectionView 实现长按拖拽功能
導讀
簡單用Swift寫了一個collectionview的拖拽點擊排序效果;
拖拽排序是新聞類的App可以說是必有的交互設計,如今日頭條,網易新聞等。
效果
主要代碼
手勢長按移動
1.給CollectionViewCell添加一個長按手勢.
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.開始長按時對cell進行截圖或拷貝一個cell,并隱藏cell.
//MARK: - 長按開始
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(此處可以根據需求隨意修改)
dragingItem.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)
}
3.在手勢移動的時候,找到目標是的indexPatch,再調用系統的api交換這個cell和隱藏cell的位置,并且更新數據.
//MARK: - 移動過程
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}
// 更新數據
let obj = selectedArr[indexPath!.item]
selectedArr.remove(at: indexPath!.row)
selectedArr.insert(obj, at: targetIndexPath!.item)
//交換位置
collectionView.moveItem(at: indexPath!, to: targetIndexPath!)
//進行記錄
indexPath = targetIndexPath
}
4.手勢停止或取消時,移除view,顯示隱藏cell. (這里手勢取消也要掉用此方法)
//MARK: - 長按結束或取消
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
})
}
點擊移動
collectionView的點擊方法,我這里分為兩段,第一段為點擊處理事件,第二段為點擊添加添加標簽(編輯狀態下第一段可以點擊排序)
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.section > 0 {
// 更新數據
let obj = recommendArr[indexPath.item]
recommendArr.remove(at: indexPath.item)
selectedArr.append(obj)
//移動方法
collectionView.moveItem(at: indexPath, to: NSIndexPath(item: selectedArr.count - 1, section: 0) as IndexPath)
} else {
if isEdite {
if indexPath.item == 0 {return}
// 更新數據
let obj = selectedArr[indexPath.item]
selectedArr.remove(at: indexPath.item)
recommendArr.insert(obj, at: 0)
//移動方法
collectionView.moveItem(at: indexPath, to: NSIndexPath(item: 0, section: 1) as IndexPath)
} else {
if switchoverCallback != nil {
//處理點擊的閉包
switchoverCallback!(selectedArr, recommendArr, indexPath.item)
_ = navigationController?.popViewController(animated: true)
}
}
}
}
其他
此代碼只是一個效果,沒有怎么封裝,如果仔細看過的朋友可以知道其實沒有多么復雜
點擊移動
collectionView.moveItem(at: indexPath, to: NSIndexPath(item: 0, section: 1) as IndexPath)
拖拽移動
collectionView.moveItem(at: indexPath!, to: targetIndexPath!)
主要就是這兩個方法,其他都是處理邏輯以及視圖效果.
提示
如果你們是從iOS9開始適配的話,那么可以用系統的Api,非常簡單好用,大家這里可以自己去試試.
// 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()
源碼可以從這里下載
以上所述是小編給大家介紹的Swift下使用UICollectionView 實現長按拖拽功能,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對腳本之家網站的支持!
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