第五天:Swift拖動 item 重排 CollectionView

?參考鏈接:https://www.jianshu.com/p/96f956f1479e

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

import UIKit

enum VC: String {
    case ViewController
    case CollectionViewController
    
    func segueIdentifier() -> String {
        switch self {
        case .ViewController:
            return "SegueIdentifierViewController"
        case .CollectionViewController:
            return "SegueIdentifeirCollectionViewController"
        }
    }
}

private let CellID = "CellId"

class MCMainTableViewController: UITableViewController {

    lazy var tempArr: [VC] = {
        var arr: [VC] = [.ViewController, .CollectionViewController];
        return arr
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()

        
        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
        // self.navigationItem.rightBarButtonItem = self.editButtonItem
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return tempArr.count
    }

    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: CellID, for: indexPath)

        // Configure the cell...
        cell.textLabel?.text = tempArr[indexPath.row].rawValue

        return cell
    }
    
    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        self.performSegue(withIdentifier: tempArr[indexPath.row].segueIdentifier(), sender: tableView)
    }
    
    /*
    // Override to support conditional editing of the table view.
    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        // Return false if you do not want the specified item to be editable.
        return true
    }
    */

    /*
    // Override to support editing the table view.
    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            // Delete the row from the data source
            tableView.deleteRows(at: [indexPath], with: .fade)
        } else if editingStyle == .insert {
            // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
        }    
    }
    */

    /*
    // Override to support rearranging the table view.
    override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) {

    }
    */

    /*
    // Override to support conditional rearranging of the table view.
    override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {
        // Return false if you do not want the item to be re-orderable.
        return true
    }
    */


    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
        
        for index in 0..<tempArr.count {
            if segue.identifier == tempArr[index].segueIdentifier() {
                segue.destination.title = tempArr[index].rawValue
                break
            }
        }
    }

}

import UIKit

private let CellId: String = "CellId"

class MCViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

    lazy var tempArr: [String] = {
        var arr: [String] = []
        for i in 0..<100{
            let tempStr = "\(i)"
            arr.append(tempStr)
        }
        return arr
    }()
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        
        let longGestureRecognizer: UILongPressGestureRecognizer = UILongPressGestureRecognizer.init(target: self, action: #selector(longPressAction(_:)))
        self.collectionView.addGestureRecognizer(longGestureRecognizer)
    }

    @objc func longPressAction(_ longPressGes: UILongPressGestureRecognizer) {
        switch longPressGes.state {
        case .began:
            guard let selectIndexPath = collectionView.indexPathForItem(at: longPressGes.location(in: collectionView)) else { return }
            collectionView.beginInteractiveMovementForItem(at: selectIndexPath)
        case .changed:
            collectionView.updateInteractiveMovementTargetPosition(longPressGes.location(in: collectionView))
        case .ended:
            collectionView.endInteractiveMovement()
        default:
            collectionView.cancelInteractiveMovement()
        }
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

extension MCViewController {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return tempArr.count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CellId, for: indexPath) as! MCTextCollectionViewCell
        
        cell.textLabel.text = tempArr[indexPath.item]
        
        return cell
    }
    
    func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
        let tempCell = tempArr.remove(at: sourceIndexPath.item)
        tempArr.insert(tempCell, at: destinationIndexPath.item)
    }
}

import UIKit

private let reuseIdentifier: String = "CellID"

class MCCollectionViewController: UICollectionViewController {

    lazy var tempArr: [String] = {
        var arr: [String] = []
        for i in 0..<100 {
            let str = "\(i)"
            arr.append(str)
        }
        return arr
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Register cell classes
        
//        self.collectionView!.register(MCTextCollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using [segue destinationViewController].
        // Pass the selected object to the new view controller.
    }
    */

    // MARK: UICollectionViewDataSource

//    override func numberOfSections(in collectionView: UICollectionView) -> Int {
//        // #warning Incomplete implementation, return the number of sections
//        return 1
//    }


    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of items
        return tempArr.count
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! MCTextCollectionViewCell
        
        // Configure the cell
        cell.textLabel.text = tempArr[indexPath.item]
    
        return cell
    }
    
    override func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
        let tempCell = tempArr.remove(at: sourceIndexPath.item)
        tempArr.insert(tempCell, at: destinationIndexPath.item)
    }

    // MARK: UICollectionViewDelegate

    /*
    // Uncomment this method to specify if the specified item should be highlighted during tracking
    override func collectionView(_ collectionView: UICollectionView, shouldHighlightItemAt indexPath: IndexPath) -> Bool {
        return true
    }
    */

    /*
    // Uncomment this method to specify if the specified item should be selected
    override func collectionView(_ collectionView: UICollectionView, shouldSelectItemAt indexPath: IndexPath) -> Bool {
        return true
    }
    */

    /*
    // Uncomment these methods to specify if an action menu should be displayed for the specified item, and react to actions performed on the item
    override func collectionView(_ collectionView: UICollectionView, shouldShowMenuForItemAt indexPath: IndexPath) -> Bool {
        return false
    }

    override func collectionView(_ collectionView: UICollectionView, canPerformAction action: Selector, forItemAt indexPath: IndexPath, withSender sender: Any?) -> Bool {
        return false
    }

    override func collectionView(_ collectionView: UICollectionView, performAction action: Selector, forItemAt indexPath: IndexPath, withSender sender: Any?) {
    
    }
    */

}

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