Swift3.0 UICollectionView 刪除,拖動

UICollectionView實現了一下常見的新聞分類.  附有效果圖

 近期一直在深刻學習swift,實現了CollectionView item的頭東與刪除,用的都是系統的一些函數方法,看起來比較直觀.

 

第一步:

class HotViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {

    //聲明兩個存放字符串的數組
    var nowClassName = [String]()
    var surplusClassName = [String]()
    
    //是否排序
    var isRank = Bool()
    
    var collectionView : UICollectionView?
    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = ColorViewBG
        
        let layout = UICollectionViewFlowLayout()
        layout.itemSize = CGSize(width:80,height:35)
        //列間距,行間距,偏移
        layout.minimumInteritemSpacing = 15
        layout.minimumLineSpacing = 20
        layout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10)
        
        collectionView = UICollectionView.init(frame: self.view.bounds, collectionViewLayout: layout)
        collectionView?.delegate = self
        collectionView?.dataSource = self;
        //註冊一個cell
        collectionView!.register(HotCell.self, forCellWithReuseIdentifier:"HotCell")
        //註冊區頭
        collectionView?.register(UICollectionReusableView.self, forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: "headView")
        
        
        collectionView?.backgroundColor = ColorViewBG
        self.view.addSubview(collectionView!)
        let gesture = UILongPressGestureRecognizer(target: self, action: #selector(viewCustom(_ :)))
        
        collectionView?.addGestureRecognizer(gesture)
        
        saveData()
    }

func viewCustom(_ longPress:UILongPressGestureRecognizer){
        
        let point:CGPoint = longPress.location(in: longPress.view)
        
        let indexPath = self.collectionView?.indexPathForItem(at: point)
        
        switch longPress.state {
        case .began:
            
            self.collectionView?.beginInteractiveMovementForItem(at: indexPath!)
            break
        case .changed:
            self.collectionView?.updateInteractiveMovementTargetPosition(point)
            
            break
            
        case .ended:
            self.collectionView?.endInteractiveMovement()
            break
            
        default:
            self.collectionView?.cancelInteractiveMovement()
            break
        }
        
    }

 //添加數據
    private func saveData() {
        nowClassName += ["A-1","A-2","A-3","A-4","A-5","A-6","A-7","A-8","A-9","A-10","A-11"]
        surplusClassName += ["B-1","B-2","B-3","B-4","B-5","B-6","B-7","B-8","B-9","B-10","B-11"]

    }

 

// MARK: 代理
    //每一個區的item個數
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        
        if section == 0 {
            return nowClassName.count
        }else {
            
            if !isRank {
                return surplusClassName.count
            }else{
                 return 0
            }
        }
        
    }
    
    //分區個數
    func numberOfSections(in collectionView: UICollectionView) -> Int {
        
        if !isRank {
            return 2
        }
        
        return 1
    }
    
    //自定義cell
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "HotCell", for: indexPath) as! HotCell
        cell.backgroundColor = UIColor.red
        if indexPath.section == 0 {
            cell.label.text = nowClassName[indexPath.item]
            cell.button.addTarget(self, action: #selector(removeItem(_ :)), for: .touchUpInside)
            cell.button.tag = indexPath.row
            
            cell.button.isHidden = !isRank
            
        }else{
            cell.label.text = surplusClassName[indexPath.item]
            cell.button.isHidden = true
            
        }
        return cell
        
    }
    
    func removeItem(_ button:UIButton){

        //執行在這裏的時候,顯示的是有個分區,不然崩潰,報不明錯誤!,研究過的能夠告訴一下,不勝感激!!!
        self.collectionView?.performBatchUpdates({ 
            //數據變動
            let item = self.nowClassName[button.tag]
            self.nowClassName.remove(at: button.tag)
            self.surplusClassName.append(item)
            
            
            let indexPath = IndexPath.init(item: button.tag, section: 0)
            print(indexPath)

            let arr:[IndexPath] = [indexPath]
            self.collectionView?.deleteItems(at: arr)
            
        }, completion: { (completion) in
            
            self.collectionView?.reloadData()
        })
        
    }
    
    //是否能夠移動
    func collectionView(_ collectionView: UICollectionView, canMoveItemAt indexPath: IndexPath) -> Bool {
        
        if isRank {
            return true
        }
        return false
        
    }
    
    
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        //獲取當前 item
        //collectionView.cellForItem(at: indexPath)
        //獲取全部的item
        //collectionView.indexPathsForVisibleItems
        
        if !isRank && indexPath.section == 1{
            //先把數據更新好,由於移動後界面會自動刷新,不然會崩潰
            nowClassName.append(surplusClassName[indexPath.item])
            surplusClassName.remove(at: indexPath.item)
            
            let indexPath1 = NSIndexPath.init(item: nowClassName.count-1, section: 0)
            let indexPath2 = NSIndexPath.init(item: indexPath.item, section: 1)
           
            //從當前位置移動到新的位置
            collectionView.moveItem(at: indexPath2 as IndexPath, to: indexPath1 as IndexPath)
        }
        
    }
    
    
    //設置拖動(手勢拖動觸發)
    func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
        
//        if sourceIndexPath.section == 0 && destinationIndexPath.section == 0 {
//            collectionView.exchangeSubview(at: sourceIndexPath.item, withSubviewAt: destinationIndexPath.item)
//        }
        
    }
    
    //區頭設置
    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        
//
        //區頭
        var headerView : UICollectionReusableView?
        
        if kind == UICollectionElementKindSectionHeader{
            headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "headView", for: indexPath)
            
            //防止重用,這樣很暴力
            for view in (headerView?.subviews)!{
                view.removeFromSuperview()
            
            }
            
            let label = UILabel.init(frame: CGRect(x:20,y:0,width:160,height:30))
            if indexPath.section == 0 {
                label.text = "切換欄目"
                
                let button = UIButton.init(type: .custom)
                button.frame = CGRect(x:collectionView.frame.size.width - 100,y:0,width:80,height:30)
                button.titleLabel?.textColor = UIColor.cyan
                button.backgroundColor = UIColor.white
                
                let str = isRank ? "完成排序" : "排序刪除"
                button.setTitle(str, for: .normal)
                button.setTitleColor(UIColor.red, for: .normal)
                headerView?.addSubview(button)
               
                button.addTarget(self, action: #selector(click(_ :)), for: .touchUpInside)
                
    
            }else if indexPath.section == 1{
                label.text = "點擊添加更多欄目"
            }
            headerView?.addSubview(label)

        }
        
        return headerView!
        
        
    }
    
    func click(_ btn:UIButton){
        
        let str = isRank ? "完成排序" : "排序刪除"
        btn.setTitle(str, for: .normal)

        isRank = !isRank
        print(isRank)
        self.collectionView?.reloadData()
    }
    
    //設置HeaderView的寬高
    //MARK: UICollectionViewDelegateFlowLayout
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
        
        return CGSize(width:collectionView.frame.size.width,height:35)
        
    }

HotCell 類的實現

class HotCell: UICollectionViewCell {
    
    var label = UILabel()
    var button = UIButton()
    
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        label = UILabel.init(frame: self.bounds)
        label.textAlignment = .center
        self.addSubview(label)
        button = UIButton.init(type: .custom)
        button.backgroundColor = UIColor.white
        button.frame = CGRect(x:frame.size.width - 20,y:5,width:15,height:15)
        self.addSubview(button)
        
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}