本例可以實(shí)現(xiàn)長(zhǎng)按item實(shí)現(xiàn)拖動(dòng),重新排版collectionview,使用場(chǎng)景可以在首頁(yè)入口列表欄或者其他頁(yè)面允許用戶手動(dòng)修改入口菜單順序的地方

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ps:直接上代碼

import UIKit

class ViewController: UIViewController ,UICollectionViewDelegateFlowLayout, UICollectionViewDataSource  {

    var collectionView : UICollectionView!;
    var longPressGesture = UILongPressGestureRecognizer();
    
    var itemArr = NSMutableArray();
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        for _ in 1...100 {
            let size = CGSize(width: 100, height: 50);
            
            itemArr.add(size);
        }
        
        let layout = UICollectionViewFlowLayout.init();
        
        self.collectionView = UICollectionView(frame: self.view.bounds, collectionViewLayout: layout)
        self.collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "item");
        self.collectionView.dataSource = self;
        self.collectionView.delegate = self;
        
        longPressGesture =  UILongPressGestureRecognizer(target: self, action: #selector(handlLongPress(gesture:)) );
        longPressGesture.minimumPressDuration = 1
        self.collectionView.addGestureRecognizer(longPressGesture);
        self.view.addSubview(self.collectionView);
        
        
        
    }
    
    func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1;
    }
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return itemArr.count;
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "item", for: indexPath) as UICollectionViewCell;
    
        cell.backgroundColor = UIColor.darkGray;
        return cell;
    }
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return self.itemArr[indexPath.item] as! CGSize;
    }
    
    func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
        self.itemArr.exchangeObject(at: sourceIndexPath.item, withObjectAt: destinationIndexPath.item);
    }
    
    
    func handlLongPress(gesture: UILongPressGestureRecognizer) {
        switch gesture.state {
        case UIGestureRecognizerState.began:
            guard let selectedIndexPath = self.collectionView.indexPathForItem(at: gesture.location(in: self.collectionView)) else {
                break;
            }
            print("長(zhǎng)按開(kāi)始");
            collectionView.beginInteractiveMovementForItem(at: selectedIndexPath);
        case UIGestureRecognizerState.changed:
            collectionView.updateInteractiveMovementTargetPosition(gesture.location(in: gesture.view));
            
        case UIGestureRecognizerState.ended:
            collectionView.endInteractiveMovement()
        default:
            collectionView.cancelInteractiveMovement();
        }
        
    }

}

因?yàn)槭茄菔拘詃emo,所以collectionviewCell未封裝,layout也是使用的最簡(jiǎn)單的流水布局.

備注:后期有時(shí)間繼續(xù)更新item大小不一致的demo